input: Write a function to remove whitespaces from each string in a list of strings.
  def remove_whitespace(word_list):
      return [word.replace(' ', '') for word in word_list]
  
  assert remove_whitespace(['Hello  World  ', 'Hi  there', 'Good  Morning'])==['HelloWorld', 'Hithere', 'GoodMorning']
  assert remove_whitespace(['  Python', '  is ', 'fun  '])==['Python', 'is', 'fun']
  assert remove_whitespace(['No', 'spaces here'])==['No', 'spaceshere']
  assert remove_whitespace(['', ' ', '   '])==['', '', '']
  assert remove_whitespace([])==[]
output: def remove_whitespace(word_list):
      return [word.replace(' ', '') for word in word_list]