import json


def extract_body(event):
    """Extracts the body of the event for which this lambda is called.
    
    Arguments:
        event {dict} -- The event as received by this lambda handler
    
    Returns:
        dict -- JSON of the body, or None if the body cannot be found
    """
    body = None
    if 'body' in event:
        body = json.loads(event['body'])
    return body