<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def setup(self, hosts, artifacts, extra_artifacts, use_tsk, reason, grr_server_url, grr_username, grr_password, approvers=None, verify=True):
 """Initializes a GRR artifact collector. Args: hosts: Comma-separated list of hostnames to launch the flow on. artifacts: list of GRR-defined artifacts. extra_artifacts: list of GRR-defined artifacts to append. use_tsk: toggle for use_tsk flag on GRR flow. reason: justification for GRR access. grr_server_url: GRR server URL. grr_username: GRR username. grr_password: GRR password. approvers: list of GRR approval recipients. verify: boolean, whether to verify the GRR server's x509 certificate. """

    super(GRRArtifactCollector, self).setup(
        reason, grr_server_url, grr_username, grr_password, approvers=approvers,
        verify=verify)

    if artifacts is not None:
      self.artifacts = [item.strip() for item in artifacts.strip().split(',')]

    if extra_artifacts is not None:
      self.extra_artifacts = [item.strip() for item
                              in extra_artifacts.strip().split(',')]

    self.hostnames = [item.strip() for item in hosts.strip().split(',')]
    self.use_tsk = use_tsk