def METHOD_NAME(self, stream_name):
    date_columns = []
    schema = {}
    for field in self.streams[stream_name]:
        fieldname, fieldtype = field.split(":")
        nullable = fieldtype.endswith("?")
        if nullable:
            fieldtype = fieldtype[:-1]
        if fieldtype == "DateTime":
            date_columns.append(fieldname)
        schema[fieldname] = self.datatypedict[fieldtype]
    return schema, date_columns