Exports the supported import/export schema to a dictionary

def export_schema_to_dict(back_references):
    """Exports the supported import/export schema to a dictionary"""
    databases = [Database.export_schema(recursive=True,
                 include_parent_ref=back_references)]
    clusters = [DruidCluster.export_schema(recursive=True,
                include_parent_ref=back_references)]
    data = dict()
    if databases:
        data[DATABASES_KEY] = databases
    if clusters:
        data[DRUID_CLUSTERS_KEY] = clusters
    return data