def validate_file_extension(file_name, file_type):
    """
    Returns Boolean flag to evaluate if the file has the correct extension:
    sbml => xml
    sbtab => tsv, csv, xlsx.

    Parameters
    ----------
    file_name: str
        Name of the file.
    file_type: str
        Type of the file ('sbtab' or 'sbml').

    Returns: Bool
        Boolean flag indicating if the given file extension corresponds to the given file type.
    """
    if file_type == 'sbml' and file_name[-3:] == 'xml':
        return True
    elif file_type == 'sbml':
        return False
    else:
        pass
    if file_type == 'sbtab' and file_name[-3:] == 'tsv':
        return True
    elif file_type == 'sbtab' and file_name[-3:] == 'csv':
        return True
    elif file_type == 'sbtab' and file_name[-4:] == 'xlsx':
        return True
    elif file_type == 'sbtab':
        return False
    else:
        pass
    return False
