input: Write a python function to filter out negative numbers from a matrix and set them to 0.
  assert np.array_equal(filter_out_negative([[-1, 2, -3], [-4, 5, 6], [-7, 8, 9]]), np.array([[0, 2, 0], [0, 5, 6], [0, 8, 9]]))
  assert np.array_equal(filter_out_negative([[1, -2, 3], [-4, -5, 6], [7, 8, -9]]), np.array([[1, 0, 3], [0, 0, 6], [7, 8, 0]]))
  assert np.array_equal(filter_out_negative([[0, -1, -2], [-3, 4, -5], [6, -7, 8]]), np.array([[0, 0, 0], [0, 4, 0], [6, 0, 8]]))
output: def filter_out_negative(matrix):
      import numpy as np
      matrix = np.array(matrix)
      matrix[matrix < 0] = 0
      return matrix