code: public static SparseIntegerVector subview(SparseIntegerVector vector, 
                                                int offset, int length) {
          if (vector == null)
              throw new NullPointerException("Cannot create view of a " +
                                             "null vector");
          return new SparseIntegerVectorView(vector, offset, length);
      }
docs: Returns a subview for the given {@code IntegerVector} with a specified
  offset and length.
  
  @param vector the {@code Vector} whose values will be shown in the view
  @param offset the index of {@code v} at which the first index of this
  view starts
  @param length the length of this view.
  
  @throws IllegalArgumentException if <ul><li>{@code offset} is
  negative<li>{@code length} is less than zero<li>the sum of {@code
  offset} plus {@code length} is greater than the length of {@code
  vector}</ul>