def __init__(self, s3_conn, es_client):
self.s3_conn = s3_conn<EOL>self.es_client = es_client<EOL>
Base class for Elasticsearch indexers

Subclasses implement the index setting definition and transformation of data,
The base class handles index management and bulk indexing with ES

Args:
    s3_conn - a boto s3 connection
    es_client - an Elasticsearch indices client