'Returns keys of the given ``dictionary``.
If keys are sortable, they are returned in sorted order. The given
``dictionary`` is never altered by this keyword.
Example:
| ${keys} = | Get Dictionary Keys | ${D3} |
| ${keys} = [\'a\', \'b\', \'c\']'

def get_dictionary_keys(self, dictionary):

    keys = dictionary.keys()
    try:
        return sorted(keys)
    except TypeError:
        return list(keys)
