warnings.warn(
                "Object %d %d not defined." %
                (ref.idnum, ref.generation), PdfReadWarning
            )
            raise PdfReadError(
                "Could not find object (%d, %d)" % (ref.idnum, ref.generation)
            )

                     except ValueError:
                        # Unable to resolve the Object, returning NullObject
                        # instead.
                        warnings.warn(
                            "Unable to resolve [{}: {}], returning NullObject "
                            "instead".format(data.__class__.__name__, data)
                        )
                        return NullObject()

                     except (ValueError, PyPdfError):
                     ...