def composite_get_label_dict(field_list):
    """
    Converts a list of dictionaries containing the keys
    "field_name" and "label" into a single dictionary
    with "field_name" value as key and "label" as value.
    If label is not defined, the field name is used as
    label. 
    """
    label_dict = {}
    for field in field_list:
        name = field.get('field_name', '')
        label_dict[name] = field.get('label', name)
    return label_dict
