fix issue with various nodes ->toString() calls

Author: patinthehat

src/Searcher.php

@@ -195,12 +195,23 @@ protected function findReferences(array $ast, string $class, ?string $nodeNamePr
             }
 
             if ($node instanceof Node\Expr\MethodCall) {
+                if (! method_exists($node->name, 'toString')) {
+                    return false;
+                }
+
                 $name = $node->name->toString();
 
                 return Arr::matches($name, $names, true);
             }
 
             if ($node instanceof Node\Expr\StaticCall) {
+                if (! method_exists($node->class, 'toString')) {
+                    return false;
+                }
+                if (! method_exists($node->name, 'toString')) {
+                    return false;
+                }
+
                 $name = $node->class->toString();
                 $methodName = $node->name->toString();