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.fo.PropertyList$UnknownPropertyHandler
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.apache.fop.fo.PropertyList$UnknownPropertyHandler
  super_class: java.lang.Object
{
  private java.util.Map<java.lang.String, org.apache.fop.fo.properties.Property> unknownPropertyValues;
    descriptor: Ljava/util/Map;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/util/Map<Ljava/lang/String;Lorg/apache/fop/fo/properties/Property;>;

  private java.util.Set<org.apache.fop.fo.properties.Property> knownProperties;
    descriptor: Ljava/util/Set;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/util/Set<Lorg/apache/fop/fo/properties/Property;>;

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.apache.fop.fo.PropertyList$UnknownPropertyHandler this
         0: .line 148
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 153
            aload 0 /* this */
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
            putfield org.apache.fop.fo.PropertyList$UnknownPropertyHandler.unknownPropertyValues:Ljava/util/Map;
         2: .line 158
            aload 0 /* this */
            new java.util.HashSet
            dup
            invokespecial java.util.HashSet.<init>:()V
            putfield org.apache.fop.fo.PropertyList$UnknownPropertyHandler.knownProperties:Ljava/util/Set;
         3: .line 148
            return
        end local 0 // org.apache.fop.fo.PropertyList$UnknownPropertyHandler this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lorg/apache/fop/fo/PropertyList$UnknownPropertyHandler;

  void validatePropertyValue(java.lang.String, org.apache.fop.fo.properties.Property, org.apache.fop.fo.properties.Property);
    descriptor: (Ljava/lang/String;Lorg/apache/fop/fo/properties/Property;Lorg/apache/fop/fo/properties/Property;)V
    flags: (0x0000) 
    Code:
      stack=3, locals=4, args_size=4
        start local 0 // org.apache.fop.fo.PropertyList$UnknownPropertyHandler this
        start local 1 // java.lang.String propertyValue
        start local 2 // org.apache.fop.fo.properties.Property output
        start local 3 // org.apache.fop.fo.properties.Property property
         0: .line 161
            aload 0 /* this */
            getfield org.apache.fop.fo.PropertyList$UnknownPropertyHandler.knownProperties:Ljava/util/Set;
            aload 3 /* property */
            invokeinterface java.util.Set.contains:(Ljava/lang/Object;)Z
            ifne 4
            aload 2 /* output */
            ifnonnull 4
         1: .line 162
            aload 1 /* propertyValue */
            ifnull 5
         2: .line 163
            aload 0 /* this */
            getfield org.apache.fop.fo.PropertyList$UnknownPropertyHandler.unknownPropertyValues:Ljava/util/Map;
            aload 1 /* propertyValue */
            aload 3 /* property */
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
         3: .line 165
            goto 5
         4: .line 166
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.fop.fo.PropertyList$UnknownPropertyHandler.knownProperties:Ljava/util/Set;
            aload 3 /* property */
            invokeinterface java.util.Set.add:(Ljava/lang/Object;)Z
            pop
         5: .line 168
      StackMap locals:
      StackMap stack:
            return
        end local 3 // org.apache.fop.fo.properties.Property property
        end local 2 // org.apache.fop.fo.properties.Property output
        end local 1 // java.lang.String propertyValue
        end local 0 // org.apache.fop.fo.PropertyList$UnknownPropertyHandler this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    6     0           this  Lorg/apache/fop/fo/PropertyList$UnknownPropertyHandler;
            0    6     1  propertyValue  Ljava/lang/String;
            0    6     2         output  Lorg/apache/fop/fo/properties/Property;
            0    6     3       property  Lorg/apache/fop/fo/properties/Property;
    MethodParameters:
               Name  Flags
      propertyValue  
      output         
      property       

  java.util.Map<java.lang.String, org.apache.fop.fo.properties.Property> getUnknownPropertyValues();
    descriptor: ()Ljava/util/Map;
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.fop.fo.PropertyList$UnknownPropertyHandler this
         0: .line 171
            aload 0 /* this */
            getfield org.apache.fop.fo.PropertyList$UnknownPropertyHandler.unknownPropertyValues:Ljava/util/Map;
            areturn
        end local 0 // org.apache.fop.fo.PropertyList$UnknownPropertyHandler this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/fop/fo/PropertyList$UnknownPropertyHandler;
    Signature: ()Ljava/util/Map<Ljava/lang/String;Lorg/apache/fop/fo/properties/Property;>;
}
SourceFile: "PropertyList.java"
NestHost: org.apache.fop.fo.PropertyList
InnerClasses:
  private UnknownPropertyHandler = org.apache.fop.fo.PropertyList$UnknownPropertyHandler of org.apache.fop.fo.PropertyList