code: function pg_create_index_query_v1 (self, ObjType, type, field, typefield, is_unique) {
  	var colname = _parse_predicate_key(ObjType, {'epoch':false}, field);
  	var query = pg_create_index_query_internal_v1(self, ObjType, type, field, typefield, is_unique);
  	var params = colname.getParams();
  	if(params.length !== 0) {
  		throw new TypeError("pg_create_index_query_v1() does not support params!");
  	}
  	return query;
  }
docs: Returns the create index query as string and throws an error if any parameters exists
  @param self
  @param ObjType
  @param type
  @param field
  @param typefield
  @param is_unique
  @return {string | *}