Program Specification: An array that can grow and shrink (as needed) at run time is generally called a dynamic array. You are to write a class named DynArray which can hold double values that adheres to the following . The physical size of the array at all times is a nonnegative power of two (smallest of which is 1) The physical size is never more than 2 times the number of elements which occupy it (with exception to when it is at size 1). Mandatory Instance variables private double [] array; private int size; private int nextIndex; Mandatory Instance methods public DynArray) // constructor // set array to a new array of double, of size one // set size to one, // and set nextIndex to zero public int arraySize) // accessor // return the value of size public int elements) // accessor // return the value of nextIndex public double at (int index) // accessor // if 0