https://github.com/eclipse-vertx/vertx-sql-client: The Reactive SQL Client (Eclipse) 
public abstract class io.vertx.sqlclient.impl.SqlConnectionBase<C extends io.vertx.sqlclient.SqlClient> extends io.vertx.sqlclient.impl.SqlClientBase<C>
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: io.vertx.sqlclient.impl.SqlConnectionBase
  super_class: io.vertx.sqlclient.impl.SqlClientBase
{
  protected final io.vertx.core.impl.ContextInternal context;
    descriptor: Lio/vertx/core/impl/ContextInternal;
    flags: (0x0014) ACC_PROTECTED, ACC_FINAL

  protected final io.vertx.sqlclient.impl.Connection conn;
    descriptor: Lio/vertx/sqlclient/impl/Connection;
    flags: (0x0014) ACC_PROTECTED, ACC_FINAL

  protected void <init>(io.vertx.core.impl.ContextInternal, io.vertx.sqlclient.impl.Connection, io.vertx.sqlclient.impl.tracing.QueryTracer, io.vertx.core.spi.metrics.ClientMetrics);
    descriptor: (Lio/vertx/core/impl/ContextInternal;Lio/vertx/sqlclient/impl/Connection;Lio/vertx/sqlclient/impl/tracing/QueryTracer;Lio/vertx/core/spi/metrics/ClientMetrics;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=3, locals=5, args_size=5
        start local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
        start local 1 // io.vertx.core.impl.ContextInternal context
        start local 2 // io.vertx.sqlclient.impl.Connection conn
        start local 3 // io.vertx.sqlclient.impl.tracing.QueryTracer tracer
        start local 4 // io.vertx.core.spi.metrics.ClientMetrics metrics
         0: .line 37
            aload 0 /* this */
            aload 3 /* tracer */
            aload 4 /* metrics */
            invokespecial io.vertx.sqlclient.impl.SqlClientBase.<init>:(Lio/vertx/sqlclient/impl/tracing/QueryTracer;Lio/vertx/core/spi/metrics/ClientMetrics;)V
         1: .line 38
            aload 0 /* this */
            aload 1 /* context */
            putfield io.vertx.sqlclient.impl.SqlConnectionBase.context:Lio/vertx/core/impl/ContextInternal;
         2: .line 39
            aload 0 /* this */
            aload 2 /* conn */
            putfield io.vertx.sqlclient.impl.SqlConnectionBase.conn:Lio/vertx/sqlclient/impl/Connection;
         3: .line 40
            return
        end local 4 // io.vertx.core.spi.metrics.ClientMetrics metrics
        end local 3 // io.vertx.sqlclient.impl.tracing.QueryTracer tracer
        end local 2 // io.vertx.sqlclient.impl.Connection conn
        end local 1 // io.vertx.core.impl.ContextInternal context
        end local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    4     0     this  Lio/vertx/sqlclient/impl/SqlConnectionBase<TC;>;
            0    4     1  context  Lio/vertx/core/impl/ContextInternal;
            0    4     2     conn  Lio/vertx/sqlclient/impl/Connection;
            0    4     3   tracer  Lio/vertx/sqlclient/impl/tracing/QueryTracer;
            0    4     4  metrics  Lio/vertx/core/spi/metrics/ClientMetrics;
    MethodParameters:
         Name  Flags
      context  
      conn     
      tracer   
      metrics  

  public C prepare(java.lang.String, io.vertx.core.Handler<io.vertx.core.AsyncResult<io.vertx.sqlclient.PreparedStatement>>);
    descriptor: (Ljava/lang/String;Lio/vertx/core/Handler;)Lio/vertx/sqlclient/SqlClient;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=3
        start local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
        start local 1 // java.lang.String sql
        start local 2 // io.vertx.core.Handler handler
         0: .line 43
            aload 0 /* this */
            aload 1 /* sql */
            invokevirtual io.vertx.sqlclient.impl.SqlConnectionBase.prepare:(Ljava/lang/String;)Lio/vertx/core/Future;
            astore 3 /* fut */
        start local 3 // io.vertx.core.Future fut
         1: .line 44
            aload 2 /* handler */
            ifnull 3
         2: .line 45
            aload 3 /* fut */
            aload 2 /* handler */
            invokeinterface io.vertx.core.Future.onComplete:(Lio/vertx/core/Handler;)Lio/vertx/core/Future;
            pop
         3: .line 47
      StackMap locals: io.vertx.core.Future
      StackMap stack:
            aload 0 /* this */
            areturn
        end local 3 // io.vertx.core.Future fut
        end local 2 // io.vertx.core.Handler handler
        end local 1 // java.lang.String sql
        end local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    4     0     this  Lio/vertx/sqlclient/impl/SqlConnectionBase<TC;>;
            0    4     1      sql  Ljava/lang/String;
            0    4     2  handler  Lio/vertx/core/Handler<Lio/vertx/core/AsyncResult<Lio/vertx/sqlclient/PreparedStatement;>;>;
            1    4     3      fut  Lio/vertx/core/Future<Lio/vertx/sqlclient/PreparedStatement;>;
    Signature: (Ljava/lang/String;Lio/vertx/core/Handler<Lio/vertx/core/AsyncResult<Lio/vertx/sqlclient/PreparedStatement;>;>;)TC;
    MethodParameters:
         Name  Flags
      sql      
      handler  

  public io.vertx.core.Future<io.vertx.sqlclient.PreparedStatement> prepare(java.lang.String);
    descriptor: (Ljava/lang/String;)Lio/vertx/core/Future;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=3, args_size=2
        start local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
        start local 1 // java.lang.String sql
         0: .line 51
            aload 0 /* this */
            invokevirtual io.vertx.sqlclient.impl.SqlConnectionBase.promise:()Lio/vertx/core/impl/future/PromiseInternal;
            astore 2 /* promise */
        start local 2 // io.vertx.core.Promise promise
         1: .line 52
            aload 0 /* this */
            new io.vertx.sqlclient.impl.command.PrepareStatementCommand
            dup
            aload 1 /* sql */
            iconst_1
            invokespecial io.vertx.sqlclient.impl.command.PrepareStatementCommand.<init>:(Ljava/lang/String;Z)V
            aload 2 /* promise */
            invokevirtual io.vertx.sqlclient.impl.SqlConnectionBase.schedule:(Lio/vertx/sqlclient/impl/command/CommandBase;Lio/vertx/core/Promise;)V
         2: .line 53
            aload 2 /* promise */
            invokeinterface io.vertx.core.Promise.future:()Lio/vertx/core/Future;
         3: .line 54
            aload 0 /* this */
            invokedynamic apply(Lio/vertx/sqlclient/impl/SqlConnectionBase;)Ljava/util/function/Function;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Ljava/lang/Object;
                  io/vertx/sqlclient/impl/SqlConnectionBase.lambda$0(Lio/vertx/sqlclient/impl/PreparedStatement;)Lio/vertx/core/Future; (7)
                  (Lio/vertx/sqlclient/impl/PreparedStatement;)Lio/vertx/core/Future;
         4: .line 55
            aload 0 /* this */
            aload 1 /* sql */
            invokedynamic apply(Lio/vertx/sqlclient/impl/SqlConnectionBase;Ljava/lang/String;)Ljava/util/function/Function;
              Bootstrap: invokestatic java.lang.invoke.LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
                Method arguments:
                  (Ljava/lang/Object;)Ljava/lang/Object;
                  io/vertx/sqlclient/impl/SqlConnectionBase.lambda$1(Ljava/lang/String;Ljava/lang/Throwable;)Lio/vertx/core/Future; (7)
                  (Ljava/lang/Throwable;)Lio/vertx/core/Future;
         5: .line 53
            invokeinterface io.vertx.core.Future.compose:(Ljava/util/function/Function;Ljava/util/function/Function;)Lio/vertx/core/Future;
            areturn
        end local 2 // io.vertx.core.Promise promise
        end local 1 // java.lang.String sql
        end local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    6     0     this  Lio/vertx/sqlclient/impl/SqlConnectionBase<TC;>;
            0    6     1      sql  Ljava/lang/String;
            1    6     2  promise  Lio/vertx/core/Promise<Lio/vertx/sqlclient/impl/PreparedStatement;>;
    Signature: (Ljava/lang/String;)Lio/vertx/core/Future<Lio/vertx/sqlclient/PreparedStatement;>;
    MethodParameters:
      Name  Flags
      sql   

  private io.vertx.core.Future lambda$0(io.vertx.sqlclient.impl.PreparedStatement);
    descriptor: (Lio/vertx/sqlclient/impl/PreparedStatement;)Lio/vertx/core/Future;
    flags: (0x1002) ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=6, locals=2, args_size=2
        start local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
        start local 1 // io.vertx.sqlclient.impl.PreparedStatement cr
         0: .line 54
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.conn:Lio/vertx/sqlclient/impl/Connection;
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.tracer:Lio/vertx/sqlclient/impl/tracing/QueryTracer;
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.metrics:Lio/vertx/core/spi/metrics/ClientMetrics;
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.context:Lio/vertx/core/impl/ContextInternal;
            aload 1 /* cr */
            aload 0 /* this */
            invokevirtual io.vertx.sqlclient.impl.SqlConnectionBase.autoCommit:()Z
            invokestatic io.vertx.sqlclient.impl.PreparedStatementImpl.create:(Lio/vertx/sqlclient/impl/Connection;Lio/vertx/sqlclient/impl/tracing/QueryTracer;Lio/vertx/core/spi/metrics/ClientMetrics;Lio/vertx/core/impl/ContextInternal;Lio/vertx/sqlclient/impl/PreparedStatement;Z)Lio/vertx/sqlclient/PreparedStatement;
            invokestatic io.vertx.core.Future.succeededFuture:(Ljava/lang/Object;)Lio/vertx/core/Future;
            areturn
        end local 1 // io.vertx.sqlclient.impl.PreparedStatement cr
        end local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/vertx/sqlclient/impl/SqlConnectionBase<TC;>;
            0    1     1    cr  Lio/vertx/sqlclient/impl/PreparedStatement;

  private io.vertx.core.Future lambda$1(java.lang.String, java.lang.Throwable);
    descriptor: (Ljava/lang/String;Ljava/lang/Throwable;)Lio/vertx/core/Future;
    flags: (0x1002) ACC_PRIVATE, ACC_SYNTHETIC
    Code:
      stack=6, locals=3, args_size=3
        start local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
        start local 2 // java.lang.Throwable err
         0: .line 56
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.conn:Lio/vertx/sqlclient/impl/Connection;
            aload 2 /* err */
            invokeinterface io.vertx.sqlclient.impl.Connection.isIndeterminatePreparedStatementError:(Ljava/lang/Throwable;)Z
            ifeq 2
         1: .line 57
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.conn:Lio/vertx/sqlclient/impl/Connection;
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.tracer:Lio/vertx/sqlclient/impl/tracing/QueryTracer;
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.metrics:Lio/vertx/core/spi/metrics/ClientMetrics;
            aload 0 /* this */
            getfield io.vertx.sqlclient.impl.SqlConnectionBase.context:Lio/vertx/core/impl/ContextInternal;
            aload 1
            aload 0 /* this */
            invokevirtual io.vertx.sqlclient.impl.SqlConnectionBase.autoCommit:()Z
            invokestatic io.vertx.sqlclient.impl.PreparedStatementImpl.create:(Lio/vertx/sqlclient/impl/Connection;Lio/vertx/sqlclient/impl/tracing/QueryTracer;Lio/vertx/core/spi/metrics/ClientMetrics;Lio/vertx/core/impl/ContextInternal;Ljava/lang/String;Z)Lio/vertx/sqlclient/PreparedStatement;
            invokestatic io.vertx.core.Future.succeededFuture:(Ljava/lang/Object;)Lio/vertx/core/Future;
            areturn
         2: .line 59
      StackMap locals:
      StackMap stack:
            aload 2 /* err */
            invokestatic io.vertx.core.Future.failedFuture:(Ljava/lang/Throwable;)Lio/vertx/core/Future;
            areturn
        end local 2 // java.lang.Throwable err
        end local 0 // io.vertx.sqlclient.impl.SqlConnectionBase this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lio/vertx/sqlclient/impl/SqlConnectionBase<TC;>;
            0    3     2   err  Ljava/lang/Throwable;
}
Signature: <C::Lio/vertx/sqlclient/SqlClient;>Lio/vertx/sqlclient/impl/SqlClientBase<TC;>;
SourceFile: "SqlConnectionBase.java"
InnerClasses:
  public final Lookup = java.lang.invoke.MethodHandles$Lookup of java.lang.invoke.MethodHandles