Validate the input data.

def _validate(self):
        """
        Validate the input data.
        """
        if self.data_format is FormatType.PYTHON:
            self.data = self.raw_data
        elif self.data_format is FormatType.JSON:
            self._validate_json()
        elif self.data_format is FormatType.YAML:
            self._validate_yaml()