A DESCRIPTION OF THE PROBLEM :
This is the document text from Oracle Docs:

public interface NClob
extends Clob

The mapping in the JavaTM programming language for the SQL NCLOB type. An SQL NCLOB is a built-in type that stores a Character Large Object using the National Character Set as a column value in a row of a database table.

The NClob interface extends the Clob interface which provides provides methods for getting the length of an SQL NCLOB value

Note: In the last line, "provides" word is repeated consecutively.