#
# ============LICENSE_START==========================================
# org.onap.vvp/engagementmgr
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# Unless otherwise specified, all software contained herein is licensed
# under the Apache License, Version 2.0 (the “License”);
# you may not use this software except in compliance with the License.
# You may obtain a copy of the License at
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#             http://www.apache.org/licenses/LICENSE-2.0
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# Unless otherwise specified, all documentation contained herein is licensed
# under the Creative Commons License, Attribution 4.0 Intl. (the “License”);
# you may not use this documentation except in compliance with the License.
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#             https://creativecommons.org/licenses/by/4.0/
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# ============LICENSE_END============================================
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# ECOMP is a trademark and service mark of AT&T Intellectual Property.
from collections import defaultdict


class KeyAwareDefaultDict(defaultdict):
    """A defaultdict whose missing-key factory
    is passed the missing key as its only argument.

    See https://docs.python.org/3/library/collections.html#defaultdict-objects

    """

    def __missing__(self, key):
        # This code is modified copypasta from help
        # (collections.defaultdict.__missing__).
        # Unfortunately there is no simpler way to override its behavior.
        if self.default_factory is None:
            raise KeyError((key,))
        self[key] = value = self.default_factory(key)
        return value