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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 from_dict(cls, connector, ip_dict):
 """Build dict fields as SubObjects if needed. Checks if lambda for building object from dict exists. _global_field_processing and _custom_field_processing rules are checked. """

        mapping = cls._global_field_processing.copy()
        mapping.update(cls._custom_field_processing)
        # Process fields that require building themselves as objects
        for field in mapping:
            if field in ip_dict:
                ip_dict[field] = mapping[field](ip_dict[field])
        return cls(connector, **ip_dict)