int[][] (Groovy JDK enhancements)

Methods Summary

Methods
Return type	Name and parameters
`List`	`flatten()` Flattens a 2D array into a new collection.
`int[][]`	`transpose()` A transpose method for 2D int arrays.

- Methods Detail
  - public List flatten()
    
    Flattens a 2D array into a new collection. The items are copied row by row.
    Example usage:
```
int[][] array = [[0, 1], [2, 3]]
assert array.flatten() == [0, 1, 2, 3]
```
    Returns:
    
    a Collection of the array elements
    
    Since:
    
    5.0.0
  - public int[][] transpose()
    
    A transpose method for 2D int arrays.
    Example usage:
```
int[][] nums = [[10, 15, 20], [30, 35, 40]]
int[][] expected = [[10, 30], [15, 35], [20, 40]]
assert nums.transpose() == expected
```
    Returns:
    
    the transposed 2D int array
    
    Since:
    
    3.0.8