def _starts_with_drive_letter(self, file_path):
        """Return True if file_path starts with a drive letter.

        Args:
            file_path: the full path to be examined.

        Returns:
            `True` if drive letter support is enabled in the filesystem and
            the path starts with a drive letter.
        """
        colon = self._matching_string(file_path, ':')
        return (self.is_windows_fs and len(file_path) >= 2 and
                file_path[:1].isalpha and (file_path[1:2]) == colon)
Return True if file_path starts with a drive letter.

        Args:
            file_path: the full path to be examined.

        Returns:
            `True` if drive letter support is enabled in the filesystem and
            the path starts with a drive letter.