How to use the icecream.ic.argToStringFunction function in icecream

def configureIcecreamOutput(prefix=None, outputFunction=None,
                            argToStringFunction=None, includeContext=None):
    oldPrefix = ic.prefix
    oldOutputFunction = ic.outputFunction
    oldArgToStringFunction = ic.argToStringFunction
    oldIncludeContext = ic.includeContext

    if prefix:
        ic.configureOutput(prefix=prefix)
    if outputFunction:
        ic.configureOutput(outputFunction=outputFunction)
    if argToStringFunction:
        ic.configureOutput(argToStringFunction=argToStringFunction)
    if includeContext:
        ic.configureOutput(includeContext=includeContext)

    yield

    ic.configureOutput(
        oldPrefix, oldOutputFunction, oldArgToStringFunction,
        oldIncludeContext)

def testMultilineValueWrapped(self):
        # Multiline values are line wrapped.
        multilineStr = 'line1\nline2'
        with disableColoring(), captureStandardStreams() as (out, err):
            ic(multilineStr)
        pair = parseOutputIntoPairs(out, err, 2)[0][0]
        assert pair == ('multilineStr', ic.argToStringFunction(multilineStr))

def testMultipleArgumentsLongLineWrapped(self):
        # A single long line with multiple variables is line wrapped.
        val = '*' * int(ic.lineWrapWidth / 4)
        valStr = ic.argToStringFunction(val)

        v1 = v2 = v3 = v4 = val
        with disableColoring(), captureStandardStreams() as (out, err):
            ic(v1, v2, v3, v4)

        pairs = parseOutputIntoPairs(out, err, 4)
        assert pairs == [[(k, valStr)] for k in ['v1', 'v2', 'v3', 'v4']]

        lines = err.getvalue().splitlines()
        assert (
            lines[0].startswith(ic.prefix) and
            lines[1].startswith(' ' * len(ic.prefix)) and
            lines[2].startswith(' ' * len(ic.prefix)) and
            lines[3].startswith(' ' * len(ic.prefix)))

def testSingleArgumentLongLineNotWrapped(self):
        # A single long line with one argument is not line wrapped.
        longStr = '*' * (ic.lineWrapWidth + 1)
        with disableColoring(), captureStandardStreams() as (out, err):
            ic(longStr)
        pair = parseOutputIntoPairs(out, err, 1)[0][0]
        assert len(err.getvalue()) > ic.lineWrapWidth
        assert pair == ('longStr', ic.argToStringFunction(longStr))

def testIncludeContextMultiLine(self):
        multilineStr = 'line1\nline2'
        with configureIcecreamOutput(includeContext=True):
            with disableColoring(), captureStandardStreams() as (out, err):
                ic(multilineStr)

        firstLine = err.getvalue().splitlines()[0]
        assert lineIsContext(firstLine)

        pair = parseOutputIntoPairs(out, err, 3)[1][0]
        assert pair == ('multilineStr', ic.argToStringFunction(multilineStr))