input: Write a function to store and print the multiplication table of a given number. If the number is negative, the function should print an empty string.
  assert print_multiplication_table(5) == '''5 x 1 = 5
  5 x 2 = 10
  5 x 3 = 15
  5 x 4 = 20
  5 x 5 = 25
  5 x 6 = 30
  5 x 7 = 35
  5 x 8 = 40
  5 x 9 = 45
  5 x 10 = 50'''
  assert print_multiplication_table(-5) == ''
  assert print_multiplication_table(0) == '''0 x 1 = 0
  0 x 2 = 0
  0 x 3 = 0
  0 x 4 = 0
  0 x 5 = 0
  0 x 6 = 0
  0 x 7 = 0
  0 x 8 = 0
  0 x 9 = 0
  0 x 10 = 0'''
output: def print_multiplication_table(number):
      if number < 0:
          return ''
      result = ''
      for i in range(1, 11):
          result += f"{number} x {i} = {number * i}\n"
      return result.strip()