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) 
class org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder implements org.apache.fop.render.pdf.PDFStructureTreeBuilder$StructureElementBuilder
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder
  super_class: java.lang.Object
{
  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder this
         0: .line 327
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/fop/render/pdf/PDFStructureTreeBuilder$PlaceholderBuilder;

  public org.apache.fop.pdf.PDFStructElem build(org.apache.fop.pdf.StructureHierarchyMember, org.xml.sax.Attributes, org.apache.fop.pdf.PDFFactory, org.apache.fop.events.EventBroadcaster);
    descriptor: (Lorg/apache/fop/pdf/StructureHierarchyMember;Lorg/xml/sax/Attributes;Lorg/apache/fop/pdf/PDFFactory;Lorg/apache/fop/events/EventBroadcaster;)Lorg/apache/fop/pdf/PDFStructElem;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=6, args_size=5
        start local 0 // org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder this
        start local 1 // org.apache.fop.pdf.StructureHierarchyMember parent
        start local 2 // org.xml.sax.Attributes attributes
        start local 3 // org.apache.fop.pdf.PDFFactory pdfFactory
        start local 4 // org.apache.fop.events.EventBroadcaster eventBroadcaster
         0: .line 331
            new org.apache.fop.pdf.PDFStructElem$Placeholder
            dup
            aload 1 /* parent */
            invokespecial org.apache.fop.pdf.PDFStructElem$Placeholder.<init>:(Lorg/apache/fop/pdf/PDFObject;)V
            astore 5 /* elem */
        start local 5 // org.apache.fop.pdf.PDFStructElem elem
         1: .line 332
            aload 1 /* parent */
            aload 5 /* elem */
            invokevirtual org.apache.fop.pdf.StructureHierarchyMember.addKid:(Lorg/apache/fop/pdf/PDFObject;)V
         2: .line 333
            aload 5 /* elem */
            areturn
        end local 5 // org.apache.fop.pdf.PDFStructElem elem
        end local 4 // org.apache.fop.events.EventBroadcaster eventBroadcaster
        end local 3 // org.apache.fop.pdf.PDFFactory pdfFactory
        end local 2 // org.xml.sax.Attributes attributes
        end local 1 // org.apache.fop.pdf.StructureHierarchyMember parent
        end local 0 // org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder this
      LocalVariableTable:
        Start  End  Slot              Name  Signature
            0    3     0              this  Lorg/apache/fop/render/pdf/PDFStructureTreeBuilder$PlaceholderBuilder;
            0    3     1            parent  Lorg/apache/fop/pdf/StructureHierarchyMember;
            0    3     2        attributes  Lorg/xml/sax/Attributes;
            0    3     3        pdfFactory  Lorg/apache/fop/pdf/PDFFactory;
            0    3     4  eventBroadcaster  Lorg/apache/fop/events/EventBroadcaster;
            1    3     5              elem  Lorg/apache/fop/pdf/PDFStructElem;
    MethodParameters:
                  Name  Flags
      parent            
      attributes        
      pdfFactory        
      eventBroadcaster  
}
SourceFile: "PDFStructureTreeBuilder.java"
NestHost: org.apache.fop.render.pdf.PDFStructureTreeBuilder
InnerClasses:
  public Placeholder = org.apache.fop.pdf.PDFStructElem$Placeholder of org.apache.fop.pdf.PDFStructElem
  private PlaceholderBuilder = org.apache.fop.render.pdf.PDFStructureTreeBuilder$PlaceholderBuilder of org.apache.fop.render.pdf.PDFStructureTreeBuilder
  private abstract StructureElementBuilder = org.apache.fop.render.pdf.PDFStructureTreeBuilder$StructureElementBuilder of org.apache.fop.render.pdf.PDFStructureTreeBuilder