def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
def set_categories(self, categories: List[str]):
        """Sets the categories for Confusion Matrix.

        Args:
          categories: List of strings specifying the categories.
        """
        self._categories = []
        annotation_specs = []
        for category in categories:
            annotation_spec = {'displayName': category}
            self._categories.append(category)
            annotation_specs.append(annotation_spec)

        self._values['annotationSpecs'] = annotation_specs
        self._matrix = [[0
                         for i in range(len(self._categories))]
                        for j in range(len(self._categories))]
        self._values['row'] = self._matrix