code: @Override
      public Blob getBlob(int index) {
          synchronized (lock) {
              return (Blob) getMValue(internalArray, index).asNative(internalArray);
          }
      }
docs: Gets value at the given index as a Blob.
  Returns null if the value doesn't exist, or its value is not a Blob.
  
  @param index the index. This value must not exceed the bounds of the array.
  @return the Blob value or null.