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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def copyright2marc(self, key, value):
 """Populate the ``542`` MARC field."""

    E_MAP = {
        'publication': 'Article',
    }

    e_value = value.get('material')

    return {
        'd': value.get('holder'),
        'e': E_MAP.get(e_value),
        'f': value.get('statement'),
        'g': value.get('year'),
        'u': value.get('url'),
    }