'Describe an Elastic MapReduce step
:type cluster_id: str
:param cluster_id: The cluster id of interest
:type step_id: str
:param step_id: The step id of interest'

def describe_step(self, cluster_id, step_id):

    params = {'ClusterId': cluster_id, 'StepId': step_id}
    return self.get_object('DescribeStep', params, HadoopStep)
