<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def for_instances(cls, data, multi=None):
 """ returns a Capabilities object specific for this data. The minimum number of instances is not set, the check for multi-instance data is optional. :param data: the data to generate the capabilities for :type data: Instances :param multi: whether to check the structure, too :type multi: bool :return: the generated capabilities :rtype: Capabilities """

        if multi is None:
            return Capabilities(javabridge.static_call(
                "weka/core/Capabilities", "forInstances",
                "(Lweka/core/Instances;)Lweka/core/Capabilities;", data.jobject))
        else:
            return Capabilities(javabridge.static_call(
                "weka/core/Capabilities", "forInstances",
                "(Lweka/core/Instances;Z)Lweka/core/Capabilities;", data.jobject, multi))