from pants.testutil.rule_runner import RuleRunner def test_hello_world(): rr = RuleRunner() # Create a file named `hello.txt` with contents "world" rr.write_files({"hello.txt": "world"})In this example, we create a new instance of RuleRunner named `rr` and then use it to simulate writing a file named "hello.txt" with contents "world." Package library: Python-Pants(Package of Pants build system)