docs: def validate_input(function):
      """Decorator that validates the kwargs of the function passed to it."""
      @wraps(function)
      def wrapper(*args, **kwargs):
          try:
              name = function.__name__ + '_validator'  # find validator name
              globals()[name](kwargs)  # call validation function
              return function(*args, **kwargs)
          except KeyError:
              raise Exception("Could not find validation schema for the"
                              " function " + function.__name__)
      return wrapper