unknown example

        $errors = new ErrorCollection([
            TestError::error(),
            TestError::error(),
            TestError::error(),
            TestError::error(),
            TestError::warn(),
            TestError::warn(),
            TestError::warn(),
            TestError::notice(),
            TestError::notice(),
            TestError::unknown(),
        ]);

        static::assertCount(4, $errors->getErrors());
        static::assertCount(3, $errors->getWarnings());
        static::assertCount(2, $errors->getNotices());
        static::assertCount(1, $errors->filterByErrorLevel(TestError::LEVEL_UNKNOWN));
        static::assertCount(10, $errors->getElements());
        static::assertTrue($errors->blockResubmit());
    }

    public function testEmptyDoesNotThrow(): void
    {

$official = substr($this->file->headers['content-type'], 0, $pos);
            }
            else
            {
                $official = $this->file->headers['content-type'];
            }
            $official = trim(strtolower($official));

            if ($official === 'unknown/unknown'
                || $official === 'application/unknown')
            {
                return $this->unknown();
            }
            elseif (substr($official, -4) === '+xml'
                || $official === 'text/xml'
                || $official === 'application/xml')
            {
                return $official;
            }
            elseif (substr($official, 0, 6) === 'image/')
            {
                if ($return = $this->image())
                {