How do I implement this using Java?

33 class Grid This class represents a two-dimensional ArrayList of some type of value. We will use a few different kinds of grids in the project; this will help you avoid lengthier types like List> values. We' ve enforced use of ArrayList,just go with it. 3.3.2 methods public Grid(int numRows, int numcols). Creates a Grid of the indicated size, with null at each location. public Grid(T[ili ingrid). Assumes the input is rectangular, and creates/fills the values field from its contents