input: Write a function in Python to search for a given word in a large document. The function should return the line number of the document where the word is found. If the word is not found, the function should return -1.
  
  def findWord(document, word):
   lines = document.split('\n')
   line_number = -1
   for i, line in enumerate(lines):
   if word in line:
   line_number = (i + 1)
   break
   return line_number
  
  largeDocument = 'This is the first line of the document.\nThis is the second line of the document.\nThis is the third line of the document.';
  word = 'second'
  
  assert findWord(largeDocument, word) == 2
  assert findWord(largeDocument, 'fourth') == -1
  assert findWord(largeDocument, 'first') == 1
  assert findWord(largeDocument, 'third') == 3
output: def findWord(document, word):
   lines = document.split('\n')
   line_number = -1
   for i, line in enumerate(lines):
   if word in line:
   line_number = (i + 1)
   break
   return line_number