import sys

IS_PY35 = sys.version_info >= (3, 5)

def empty():

    """

    >>> empty()

    {}

    """

    d = {}

    return d

def keyvalue(key, value):

    """

    >>> keyvalue(1, 2)

    {1: 2}

    """

    d = {key:value}

    return d

def keyvalues(key1, value1, key2, value2):

    """

    >>> sorted(keyvalues(1, 2, 3, 4).items())

    [(1, 2), (3, 4)]

    """

    d = {key1:value1, key2:value2}

    return d

def keyvalues2(key1, value1, key2, value2):

    """

    >>> sorted(keyvalues2(1, 2, 3, 4).items())

    [(1, 2), (3, 4)]

    """

    d = {key1:value1, key2:value2,}

    return d

def constant():

    """

    >>> len(constant())

    2

    >>> print(constant()['parrot'])

    resting

    >>> print(constant()['answer'])

    42

    """

    d = {u"parrot":u"resting", u"answer":42}

    return d

def dict_call():

    """

    >>> print(dict_call()['parrot'])

    resting

    >>> print(dict_call()['answer'])

    42

    """

    d = dict(parrot=u"resting", answer=42)

    return d

def dict_call_dict():

    """

    >>> print(dict_call_dict()['parrot'])

    resting

    >>> print(dict_call_dict()['answer'])

    42

    """

    d = dict(dict(parrot=u"resting", answer=42))

    return d

def dict_call_kwargs():

    """

    >>> print(dict_call_kwargs()['parrot1'])

    resting

    >>> print(dict_call_kwargs()['parrot2'])

    resting

    >>> print(dict_call_kwargs()['answer1'])

    42

    >>> print(dict_call_kwargs()['answer2'])

    42

    """

    kwargs = dict(parrot1=u"resting", answer1=42)

    d = dict(parrot2=u"resting", answer2=42, **kwargs)

    return d

def items_of_dict_call():

    """

    >>> items_of_dict_call()

    [('answer1', 42), ('answer2', 42), ('parrot1', 'resting'), ('parrot2', 'resting')]

    """

    kwargs = dict(parrot1="resting", answer1=42)

    items = dict(kwargs.items(), parrot2="resting", answer2=42, **kwargs).items()

    return sorted(items)

def item_creation_sideeffect(L, sideeffect, unhashable):

    """

    >>> def sideeffect(x):

    ...     L.append(x)

    ...     return x

    >>> def unhashable(x):

    ...     L.append(x)

    ...     return [x]

    >>> L = []

    >>> item_creation_sideeffect(L, sideeffect, unhashable)  # doctest: +ELLIPSIS

    Traceback (most recent call last):

    TypeError: ...unhashable...

    >>> L

    [2, 4]

    >>> L = []

    >>> {1:2, sideeffect(2): 3, 3: 4, unhashable(4): 5, sideeffect(5): 6}  # doctest: +ELLIPSIS

    Traceback (most recent call last):

    TypeError: ...unhashable...

    >>> L if IS_PY35 else (L + [5])

    [2, 4, 5]

    """

    return {1:2, sideeffect(2): 3, 3: 4, unhashable(4): 5, sideeffect(5): 6}