def _read_content_or_path(content_or_path):
if "<STR_LIT:\n>" in content_or_path.strip():<EOL><INDENT>return content_or_path<EOL><DEDENT>if not os.path.exists(content_or_path):<EOL><INDENT>raise IOError("<STR_LIT>" % content_or_path)<EOL><DEDENT>with open(content_or_path) as f:<EOL><INDENT>return f.read()<EOL><DEDENT>
If `content_or_path` contains ``\\n``, return it. Else assume, that it is
path and read file at that path.

Args:
    content_or_path (str): Content or path to the file.

Returns:
    str: Content.

Raises:
    IOError: whhen the file is not found.