clean up

Author: hauner

json-schema-validator/src/main/java/io/openapiprocessor/jsonschema/schema/SchemaStore.java

@@ -266,18 +266,15 @@ private SchemaVersion getMetaSchemaVersion(URI schemaUri, SchemaVersion version)
  throw new RuntimeException ();
  }
 
- if (!isObject(document))
- return null;
-
- return asObject(document);
+ return asObjectOrNull(document);
  }
 
  private Vocabularies getVocabularies (Map<String, @Nullable Object> document, SchemaVersion version) {
  Object vocabularyValue = document.get(Keywords.VOCABULARY);
  if (!isObject(vocabularyValue))
  return Vocabularies.ALL;
 
- Map<String, Object> vocabularyObject = (Map<String, Object>)asObject(vocabularyValue);
+ Map<String, Object> vocabularyObject = asObject(vocabularyValue);
 
  Map<URI, Boolean> vocabularies = new LinkedHashMap<> ();
  vocabularyObject.forEach ((propKey, propValue) -> {