input: Write a function to format a given piece of text with different options for font-style, size, and color. The function should return the formatted text as a string. If no options are provided, the text should be formatted with default values for font ("Times New Roman"), size ("14px"), and color ("#000000").
  assert format_text('Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer ut lectus vel nisi consequat bibendum ac a erat. Aliquam non velit sit amet arcu placerat vulputate a ut nibh.')=='<span style=\'font-family: Times New Roman\' font-size: 14px color: #000000\'>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer ut lectus vel nisi consequat bibendum ac a erat. Aliquam non velit sit amet arcu placerat vulputate a ut nibh.</span>'
  assert format_text('Sample text', 'Arial', '16px', '#FF0000')=='<span style=\'font-family: Arial\' font-size: 16px color: #FF0000\'>Sample text</span>'
  assert format_text('Hello World', size='20px')=='<span style=\'font-family: Times New Roman\' font-size: 20px color: #000000\'>Hello World</span>'
  assert format_text('Testing', color='#00FF00')=='<span style=\'font-family: Times New Roman\' font-size: 14px color: #00FF00\'>Testing</span>'
  assert format_text('Default formatting')=='<span style=\'font-family: Times New Roman\' font-size: 14px color: #000000\'>Default formatting</span>'
output: def format_text(text, font='Times New Roman', size='14px', color='#000000'):
      return f'<span style=\'font-family: {font}\' font-size: {size} color: {color}\'>{text}</span>'