def extractNameComponents(value):
  """This function tries to extract a family name and a last name from the input and returns them as a tuple.

  >>> extractNameComponents('Lieber, Sven')
  ('Lieber', 'Sven')
  >>> extractNameComponents('van Gogh, Vincent')
  ('van Gogh', 'Vincent')

  Empty strings are returned if it did not work. If there is only one value, we assume the family name
  >>> extractNameComponents('')
  ('', '')
  >>> extractNameComponents('van Gogh')
  ('van Gogh', '')
  >>> extractNameComponents('Hermann')
  ('Hermann', '')
  """
  familyName = ''
  givenName = ''

  if value != '':
  
    components = value.split(',')
    if len(components) == 0:
      familyName = value
    elif len(components) == 1:
      familyName = components[0].strip()
    elif len(components) > 1:
      familyName = components[0].strip()
      givenName = components[1].strip()
 
  return (familyName, givenName)