Parse a structured model group as obtained from a YAML file

    Path can be given as a string or a context.

def parse_model_group(path, group):
    """Parse a structured model group as obtained from a YAML file

    Path can be given as a string or a context.
    """

    context = FilePathContext(path)

    for reaction_id in group.get('reactions', []):
        yield reaction_id

    # Parse subgroups
    for reaction_id in parse_model_group_list(
            context, group.get('groups', [])):
        yield reaction_id