Revert "fixes #200, library prefixes for unknown imports"

lib/src/utils.dart

Index: lib/src/utils.dart
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index 9f21703d7deae66f079227fafa1807afc6f289ae..4c7339520c673f724b77c967c1d74164a4615bbe 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -207,15 +207,8 @@ _MemberTypeGetter _memberTypeGetter(ExecutableElement member) {
   return f;
 }
 
-bool isDynamicTarget(Expression node) {
-  if (node == null) return false;
-  var type = node.staticType;
-
-  // This is an unknown identifier, like an import that doesn't resolve.
-  if (type == null) return true;
-
-  return type.isDynamic && !isLibraryPrefix(node);
-}
+bool isDynamicTarget(Expression node) =>
+    node != null && !isLibraryPrefix(node) && node.staticType.isDynamic;
 
 bool isLibraryPrefix(Expression node) =>
     node is SimpleIdentifier && node.staticElement is PrefixElement;