code: public TypeSignature getTypeDescriptor() {
          if (typeDescriptorStr == null) {
              return null;
          }
          if (typeDescriptor == null) {
              try {
                  typeDescriptor = TypeSignature.parse(typeDescriptorStr, declaringClassName);
                  typeDescriptor.setScanResult(scanResult);
              } catch (final ParseException e) {
                  throw new IllegalArgumentException(e);
              }
          }
          return typeDescriptor;
      }
docs: Returns the parsed type descriptor for the field, if available.
  
  @return The parsed type descriptor for the field, if available, else returns null.