'Describes a specified task or tasks.
:type cluster: string
:param cluster: The short name or full Amazon Resource Name (ARN) of
the cluster that hosts the task you want to describe. If you do not
specify a cluster, the default cluster is assumed.
:type tasks: list
:param tasks: A space-separated list of task UUIDs or full Amazon
Resource Name (ARN) entries.'

def describe_tasks(self, tasks, cluster=None):

    params = {}
    self.build_list_params(params, tasks, 'tasks.member')
    if (cluster is not None):
        params['cluster'] = cluster
    return self._make_request(action='DescribeTasks', verb='POST', path='/', params=params)
