input: Write a function to remove all whitespaces from each string in a list of strings. If the input list is empty, return an empty list.
  assert remove_whitespace(['Hello  World  ', 'Hi  there', 'Good  Morning'])==['HelloWorld', 'Hithere', 'GoodMorning']
  assert remove_whitespace([])==[]
output: def remove_whitespace(strings):
      return [''.join(s.split()) for s in strings]