old_contents: import sys
  if sys.version_info[0] < 3:
      next = lambda x: x.next()
      bytes = str
      str = unicode
  
  
  def verify_semantic_version(val):
      parts = val.split('.')
      if len(parts) != 3:
          raise ValueError(
              "version '{}' does not follow semantic versioning".format(val))
      return str(val)
  
new_contents: import sys
  if sys.version_info[0] < 3:
      next = lambda x: x.next()
      bytes = str
      str = unicode
  
  
  def verify_semantic_version(version):
      """Verify that semantic versioning (http://semver.org/) is being
      followed. In particular, the version should have a major version,
      minor version, and patch version, separated by periods.
  
      """
      parts = version.split('.')
      if len(parts) != 3:
          raise ValueError(
              "version '{}' does not follow semantic versioning".format(version))
      return str(version)
  
subject: Add docstring to verify_semantic_version