docs: def get_ec(self, ec_handle):
          '''Get a reference to the execution context with the given handle.
  
          @param ec_handle The handle of the execution context to look for.
          @type ec_handle str
          @return A reference to the ExecutionContext object corresponding to
          the ec_handle.
          @raises NoECWithHandleError
  
          '''
          with self._mutex:
              for ec in self.owned_ecs:
                  if ec.handle == ec_handle:
                      return ec
              for ec in self.participating_ecs:
                  if ec.handle == ec_handle:
                      return ec
              raise exceptions.NoECWithHandleError