<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _read_plain_json(file_path, check_bse):
 """ Reads a JSON file A simple wrapper around json.load that only takes the file name If the file does not exist, an exception is thrown. If the file does exist, but there is a problem with the JSON formatting, the filename is added to the exception information. If check_bse is True, this function also make sure the 'molssi_bse_schema' key exists in the file. Parameters file_path : str Full path to the file to read check_bse: bool If True, check to make sure the bse schema information is included. If not found, an exception is raised """


    if not os.path.isfile(file_path):
        raise FileNotFoundError('JSON file \'{}\' does not exist, is not '
                                'readable, or is not a file'.format(file_path))

    try:
        if file_path.endswith('.bz2'):
            with bz2.open(file_path, 'rt', encoding=_default_encoding) as f:
                js = json.load(f)
        else:
            with open(file_path, 'r', encoding=_default_encoding) as f:
                js = json.load(f)

    except json.decoder.JSONDecodeError as ex:
        raise RuntimeError("File {} contains JSON errors".format(file_path)) from ex

    if check_bse is True:
        # Check for molssi_bse_schema key
        if 'molssi_bse_schema' not in js:
            raise RuntimeError('File {} does not appear to be a BSE JSON file'.format(file_path))

    return js