'Deletes a key from the bucket.  If a version_id is provided,
only that version of the key will be deleted.
:type key_name: string
:param key_name: The key name to delete
:type version_id: string
:param version_id: The version ID (optional)
:type mfa_token: tuple or list of strings
:param mfa_token: A tuple or list consisting of the serial
number from the MFA device and the current value of the
six-digit token associated with the device.  This value is
required anytime you are deleting versioned objects from a
bucket that has the MFADelete option on the bucket.
:rtype: :class:`boto.s3.key.Key` or subclass
:returns: A key object holding information on what was
deleted.  The Caller can see if a delete_marker was
created or removed and what version_id the delete created
or removed.'

def delete_key(self, key_name, headers=None, version_id=None, mfa_token=None):

    if (not key_name):
        raise ValueError('Empty    key    names    are    not    allowed')
    return self._delete_key_internal(key_name, headers=headers, version_id=version_id, mfa_token=mfa_token, query_args_l=None)
