https://openjdk.java.net/ 
public interface javax.lang.model.type.TypeVariable extends javax.lang.model.type.ReferenceType
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: javax.lang.model.type.TypeVariable
  super_class: java.lang.Object
{
  public abstract javax.lang.model.element.Element asElement();
    descriptor: ()Ljavax/lang/model/element/Element;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract javax.lang.model.type.TypeMirror getUpperBound();
    descriptor: ()Ljavax/lang/model/type/TypeMirror;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract javax.lang.model.type.TypeMirror getLowerBound();
    descriptor: ()Ljavax/lang/model/type/TypeMirror;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
SourceFile: "TypeVariable.java"