Human: how to mask a numpy array. Assistant: 
Here is a Python program to mask a numpy array

import numpy as np

def _mask_array(array, mask):
  """
  Args:
    array: Numpy array to be masked.
    mask: Boolean mask to be applied to the array.
  Returns:
    Numpy array with the mask applied.
  """
  return array[mask]

# Enter the numpy array
array = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

# Enter the mask
mask = np.array([True, False, True, True, False, True, True, True, True, True])

# Calling the function
masked_array = _mask_array(array, mask)

# Printing the masked array
print(masked_array)

#Example Output
# [ 1  3  4  6  7  8  9 10]

#Remember to inspect code for bugs.