in lib/eventstream_rpc_utils.ts [198:204]
function throwInvalidPropertyValueError(valueDescription: string, propertyName?: string, type?: string) : void {
if (propertyName && type) {
throw eventstream_rpc.createRpcError(eventstream_rpc.RpcErrorType.ValidationError, `Property '${propertyName}' of type '${type}' must be ${valueDescription}`);
} else {
throw eventstream_rpc.createRpcError(eventstream_rpc.RpcErrorType.ValidationError, `Property must be ${valueDescription}`);
}
}