code: def _WorkerCommand_environment(self):
          
          worker = self.workersArguments
          c = []
          if worker.prolog:
              c.extend([
                  "source",
                  worker.prolog,
                  "&&",
              ])
          if worker.pythonPath and not self.isLocal():
              # Tried to make it compliant to all shell variants.
              c.extend([
                  "env",
                  "PYTHONPATH={0}:$PYTHONPATH".format(worker.pythonPath),
              ])
          elif worker.pythonPath and self.isLocal():
              # Tried to make it compliant to all shell variants.
              c.extend([
                  "env",
                  "PYTHONPATH={0}:{1}".format(
                      worker.pythonPath,
                      os.environ.get("PYTHONPATH", ""),
                  ),
              ])
          return c
docs: Return list of shell commands to prepare the environment for
             bootstrap.