http://xmlgraphics.apache.org/fop/: Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF. (Apache Software Foundation) 
public class org.apache.fop.events.Event$ParamsBuilder
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.fop.events.Event$ParamsBuilder
  super_class: java.lang.Object
{
  private java.util.Map<java.lang.String, java.lang.Object> params;
    descriptor: Ljava/util/Map;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/util/Map<Ljava/lang/String;Ljava/lang/Object;>;

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.fop.events.Event$ParamsBuilder this
         0: .line 164
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.apache.fop.events.Event$ParamsBuilder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/fop/events/Event$ParamsBuilder;

  public org.apache.fop.events.Event$ParamsBuilder param(java.lang.String, java.lang.Object);
    descriptor: (Ljava/lang/String;Ljava/lang/Object;)Lorg/apache/fop/events/Event$ParamsBuilder;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // org.apache.fop.events.Event$ParamsBuilder this
        start local 1 // java.lang.String name
        start local 2 // java.lang.Object value
         0: .line 174
            aload 0 /* this */
            getfield org.apache.fop.events.Event$ParamsBuilder.params:Ljava/util/Map;
            ifnonnull 2
         1: .line 175
            aload 0 /* this */
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
            putfield org.apache.fop.events.Event$ParamsBuilder.params:Ljava/util/Map;
         2: .line 177
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.fop.events.Event$ParamsBuilder.params:Ljava/util/Map;
            aload 1 /* name */
            aload 2 /* value */
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
         3: .line 178
            aload 0 /* this */
            areturn
        end local 2 // java.lang.Object value
        end local 1 // java.lang.String name
        end local 0 // org.apache.fop.events.Event$ParamsBuilder this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    4     0   this  Lorg/apache/fop/events/Event$ParamsBuilder;
            0    4     1   name  Ljava/lang/String;
            0    4     2  value  Ljava/lang/Object;
    MethodParameters:
       Name  Flags
      name   
      value  

  public java.util.Map<java.lang.String, java.lang.Object> build();
    descriptor: ()Ljava/util/Map;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.fop.events.Event$ParamsBuilder this
         0: .line 186
            aload 0 /* this */
            getfield org.apache.fop.events.Event$ParamsBuilder.params:Ljava/util/Map;
            areturn
        end local 0 // org.apache.fop.events.Event$ParamsBuilder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/fop/events/Event$ParamsBuilder;
    Signature: ()Ljava/util/Map<Ljava/lang/String;Ljava/lang/Object;>;
}
SourceFile: "Event.java"
NestHost: org.apache.fop.events.Event
InnerClasses:
  public ParamsBuilder = org.apache.fop.events.Event$ParamsBuilder of org.apache.fop.events.Event