Add Runner.is_worker() helper method

Author: amritamishra01

pyperf/_runner.py

@@ -78,6 +78,11 @@ def __init__(self, values=None, processes=None,
                  show_name=True,
                  program_args=None, add_cmdline_args=None,
                  _argparser=None, warmups=1):
+        def is_worker(self) -> bool:
+            """Return True if the current process is a worker process."""
+            if self.args is None:
+                return False
+            return bool(self.args.worker)
 
         # Watchdog: ensure that only once instance of Runner (or a Runner
         # subclass) is created per process to prevent bad surprises