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.area.NormalFlow extends org.apache.fop.area.BlockParent
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.fop.area.NormalFlow
  super_class: org.apache.fop.area.BlockParent
{
  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: -3753538631016929004

  public void <init>(int);
    descriptor: (I)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // org.apache.fop.area.NormalFlow this
        start local 1 // int ipd
         0: .line 35
            aload 0 /* this */
            invokespecial org.apache.fop.area.BlockParent.<init>:()V
         1: .line 36
            aload 0 /* this */
            getstatic org.apache.fop.area.Trait.IS_REFERENCE_AREA:Ljava/lang/Integer;
            getstatic java.lang.Boolean.TRUE:Ljava/lang/Boolean;
            invokevirtual org.apache.fop.area.NormalFlow.addTrait:(Ljava/lang/Integer;Ljava/lang/Object;)V
         2: .line 37
            aload 0 /* this */
            iload 1 /* ipd */
            invokevirtual org.apache.fop.area.NormalFlow.setIPD:(I)V
         3: .line 38
            return
        end local 1 // int ipd
        end local 0 // org.apache.fop.area.NormalFlow this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lorg/apache/fop/area/NormalFlow;
            0    4     1   ipd  I
    MethodParameters:
      Name  Flags
      ipd   

  public void addBlock(org.apache.fop.area.Block);
    descriptor: (Lorg/apache/fop/area/Block;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // org.apache.fop.area.NormalFlow this
        start local 1 // org.apache.fop.area.Block block
         0: .line 42
            aload 0 /* this */
            aload 1 /* block */
            invokespecial org.apache.fop.area.BlockParent.addBlock:(Lorg/apache/fop/area/Block;)V
         1: .line 43
            aload 1 /* block */
            invokevirtual org.apache.fop.area.Block.isStacked:()Z
            ifeq 3
         2: .line 44
            aload 0 /* this */
            dup
            getfield org.apache.fop.area.NormalFlow.bpd:I
            aload 1 /* block */
            invokevirtual org.apache.fop.area.Block.getAllocBPD:()I
            iadd
            putfield org.apache.fop.area.NormalFlow.bpd:I
         3: .line 46
      StackMap locals:
      StackMap stack:
            return
        end local 1 // org.apache.fop.area.Block block
        end local 0 // org.apache.fop.area.NormalFlow this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    4     0   this  Lorg/apache/fop/area/NormalFlow;
            0    4     1  block  Lorg/apache/fop/area/Block;
    MethodParameters:
       Name  Flags
      block  
}
SourceFile: "NormalFlow.java"