https://www.graalvm.org/ 
final class org.graalvm.compiler.graph.Graph$MapReplacement implements org.graalvm.compiler.graph.Graph$DuplicationReplacement
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: org.graalvm.compiler.graph.Graph$MapReplacement
  super_class: java.lang.Object
{
  private final org.graalvm.collections.EconomicMap<org.graalvm.compiler.graph.Node, org.graalvm.compiler.graph.Node> map;
    descriptor: Lorg/graalvm/collections/EconomicMap;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/graalvm/collections/EconomicMap<Lorg/graalvm/compiler/graph/Node;Lorg/graalvm/compiler/graph/Node;>;

  void <init>(org.graalvm.collections.EconomicMap<org.graalvm.compiler.graph.Node, org.graalvm.compiler.graph.Node>);
    descriptor: (Lorg/graalvm/collections/EconomicMap;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.graalvm.compiler.graph.Graph$MapReplacement this
        start local 1 // org.graalvm.collections.EconomicMap map
         0: .line 1223
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 1224
            aload 0 /* this */
            aload 1 /* map */
            putfield org.graalvm.compiler.graph.Graph$MapReplacement.map:Lorg/graalvm/collections/EconomicMap;
         2: .line 1225
            return
        end local 1 // org.graalvm.collections.EconomicMap map
        end local 0 // org.graalvm.compiler.graph.Graph$MapReplacement this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/graalvm/compiler/graph/Graph$MapReplacement;
            0    3     1   map  Lorg/graalvm/collections/EconomicMap<Lorg/graalvm/compiler/graph/Node;Lorg/graalvm/compiler/graph/Node;>;
    Signature: (Lorg/graalvm/collections/EconomicMap<Lorg/graalvm/compiler/graph/Node;Lorg/graalvm/compiler/graph/Node;>;)V
    MethodParameters:
      Name  Flags
      map   

  public org.graalvm.compiler.graph.Node replacement(org.graalvm.compiler.graph.Node);
    descriptor: (Lorg/graalvm/compiler/graph/Node;)Lorg/graalvm/compiler/graph/Node;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=2
        start local 0 // org.graalvm.compiler.graph.Graph$MapReplacement this
        start local 1 // org.graalvm.compiler.graph.Node original
         0: .line 1229
            aload 0 /* this */
            getfield org.graalvm.compiler.graph.Graph$MapReplacement.map:Lorg/graalvm/collections/EconomicMap;
            aload 1 /* original */
            invokeinterface org.graalvm.collections.EconomicMap.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast org.graalvm.compiler.graph.Node
            astore 2 /* replacement */
        start local 2 // org.graalvm.compiler.graph.Node replacement
         1: .line 1230
            aload 2 /* replacement */
            ifnull 2
            aload 2 /* replacement */
            goto 3
      StackMap locals: org.graalvm.compiler.graph.Node
      StackMap stack:
         2: aload 1 /* original */
      StackMap locals:
      StackMap stack: org.graalvm.compiler.graph.Node
         3: areturn
        end local 2 // org.graalvm.compiler.graph.Node replacement
        end local 1 // org.graalvm.compiler.graph.Node original
        end local 0 // org.graalvm.compiler.graph.Graph$MapReplacement this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    4     0         this  Lorg/graalvm/compiler/graph/Graph$MapReplacement;
            0    4     1     original  Lorg/graalvm/compiler/graph/Node;
            1    4     2  replacement  Lorg/graalvm/compiler/graph/Node;
    MethodParameters:
          Name  Flags
      original  
}
SourceFile: "Graph.java"
NestHost: org.graalvm.compiler.graph.Graph
InnerClasses:
  public abstract DuplicationReplacement = org.graalvm.compiler.graph.Graph$DuplicationReplacement of org.graalvm.compiler.graph.Graph
  private final MapReplacement = org.graalvm.compiler.graph.Graph$MapReplacement of org.graalvm.compiler.graph.Graph