Usage:
extract the FQN e.g. "Some\Namespace\SomeClassName"
$fullyQualifiedClassName = (new PhpAnalyzer($fileContents))->extractFullyQualifiedClassName();
extract the namespace "Some\Namespace"
$namespace = (new PhpAnalyzer($fileContents))->extractNamespace();
extract just the class name "SomeClassName"
$className = (new PhpAnalyzer($fileContents))->extractClassName();