code: public static XField findXField(String className, String fieldName, String fieldSig, boolean isStatic)
      {
  
          return XFactory.createXField(className, fieldName, fieldSig, isStatic);
      }
docs: Look up a field with given name and signature in given class, returning
  it as an {@link XField XField} object. If a field can't be found in the
  immediate class, its superclass is search, and so forth.
  
  @param className
  name of the class through which the field is referenced
  @param fieldName
  name of the field
  @param fieldSig
  signature of the field
  @param isStatic
  true if field is static, false otherwise
  @return an XField object representing the field, or null if no such field
  could be found