Load a specification from a path.

        :param FilePath spec_path: The location of the specification to read.

def from_path(cls, spec_path):
        """
        Load a specification from a path.

        :param FilePath spec_path: The location of the specification to read.
        """
        with spec_path.open() as spec_file:
            return cls.from_document(load(spec_file))