Method contains

src/main/java/com/google/gson/MemoryRefStack.java:75–87

Performs a memory reference check to see it the obj exists in the stack. @param obj the object to search for in the stack @return true if this object is already in the stack otherwise false

(ObjectTypePair obj)

   * @return true if this object is already in the stack otherwise false
   */
  public boolean contains(ObjectTypePair obj) {
    if (obj == null) {
      return false;
    }

    for (ObjectTypePair stackObject : stack) {
      if (stackObject.getObject() == obj.getObject()
          && stackObject.type.equals(obj.type) ) {
        return true;
      }
    }
    return false;
  }
}