dumper.php
protected function describeFloatDifference($first, $second, $identical)
    {
        if (is_object($second) || is_array($second)) {
            return $this->describeGenericDifference($first, $second);
        }

        return sprintf(
            'because [%s] differs from [%s] by %s',
            $this->describeValue($first),
            $this->describeValue($second),
            abs($first - $second)
        );
    }
protected function describeFloatDifference($first, $second, $identical)
    {
        if (is_object($second) || is_array($second)) {
            return $this->describeGenericDifference($first, $second);
        }

        return sprintf(
            'because [%s] differs from [%s] by %s',
            $this->describeValue($first),
            $this->describeValue($second),
            abs($first - $second)
        );
    }
Creates a human readable description of the difference between
two floating point numbers.

@param float $first         First float.
@param mixed $second        Float to compare with.
@param bool $identical   If true then type anomolies count.

@return string              Human readable description.