def METHOD_NAME(self, field, index=None, metadata=None):
    '''
    :param field: Output field name of this analysis
    :type field: string
    :param index: If the referenced field is an array, optionally specify an index (starting from 0) to indicate a particular member of the array
    :type index: int
    :param metadata: If the referenced field is of a data object class, a string indicating the metadata that should be read, e.g. "name", "properties.propkey", "details.refgenome"
    :type metadata: string
    Returns a dict containing a valid reference to an output of this analysis.
    '''
    link = {"$dnanexus_link": {"analysis": self._dxid, "field": field}}
    if index is not None:
        link["$dnanexus_link"]["index"] = index
    if metadata is not None:
        link["$dnanexus_link"]["metadata"] = metadata
    return link