public function testIfThereIsOnlyOneElementThenReturnTheElementInsteadOfAValueList($parsedValue, $expected)
{
$decoratedParserProphecy = $this->prophesize(ParserInterface::class);
$decoratedParserProphecy->parse(Argument::any())->willReturn($parsedValue);
/** @var ParserInterface $decoratedParser */
$decoratedParser = $decoratedParserProphecy->reveal();
$parser = new StringMergerParser($decoratedParser);
$actual = $parser->parse('');
$this->assertEquals($expected, $actual);
}