def update_cloud_front_origin_access_identity(
    CloudFrontOriginAccessIdentityConfig=None, Id=None, IfMatch=None):
    """
    Update an origin access identity.
    See also: AWS API Documentation
    
    
    :example: response = client.update_cloud_front_origin_access_identity(
        CloudFrontOriginAccessIdentityConfig={
            'CallerReference': 'string',
            'Comment': 'string'
        },
        Id='string',
        IfMatch='string'
    )
    
    
    :type CloudFrontOriginAccessIdentityConfig: dict
    :param CloudFrontOriginAccessIdentityConfig: [REQUIRED]
            The identity's configuration information.
            CallerReference (string) -- [REQUIRED]A unique number that ensures the request can't be replayed.
            If the CallerReference is new (no matter the content of the CloudFrontOriginAccessIdentityConfig object), a new origin access identity is created.
            If the CallerReference is a value already sent in a previous identity request, and the content of the CloudFrontOriginAccessIdentityConfig is identical to the original request (ignoring white space), the response includes the same information returned to the original request.
            If the CallerReference is a value you already sent in a previous request to create an identity, but the content of the CloudFrontOriginAccessIdentityConfig is different from the original request, CloudFront returns a CloudFrontOriginAccessIdentityAlreadyExists error.
            Comment (string) -- [REQUIRED]Any comments you want to include about the origin access identity.
            

    :type Id: string
    :param Id: [REQUIRED]
            The identity's id.
            

    :type IfMatch: string
    :param IfMatch: The value of the ETag header that you received when retrieving the identity's configuration. For example: E2QWRUHAPOMQZL .

    :rtype: dict
    :return: {
        'CloudFrontOriginAccessIdentity': {
            'Id': 'string',
            'S3CanonicalUserId': 'string',
            'CloudFrontOriginAccessIdentityConfig': {
                'CallerReference': 'string',
                'Comment': 'string'
            }
        },
        'ETag': 'string'
    }
    
    
    """
    pass
