'HttpMock constructor.
Args:
headers: dict, header to return with response'

def __init__(self, headers=None, data=None):

    if (headers is None):
        headers = {'status': http_client.OK}
    self.data = data
    self.response_headers = headers
    self.headers = None
    self.uri = None
    self.method = None
    self.body = None
    self.headers = None
    self.requests = 0
