'Updates the config like :meth:`update` ignoring items with non-upper
keys.
.. versionadded:: 0.11'

def from_mapping(self, *mapping, **kwargs):

    mappings = []
    if (len(mapping) == 1):
        if hasattr(mapping[0], 'items'):
            mappings.append(mapping[0].items())
        else:
            mappings.append(mapping[0])
    elif (len(mapping) > 1):
        raise TypeError(('expected    at    most    1    positional    argument,    got    %d' % len(mapping)))
    mappings.append(kwargs.items())
    for mapping in mappings:
        for (key, value) in mapping:
            if key.isupper():
                self[key] = value
    return True
