@staticmethod
def safe_rt(resource_type, lower=False):
    """Format the Resource Type.

        Takes Custom Indicator types with a space character and return a *safe* string.

        (e.g. *User Agent* is converted to User_Agent or user_agent.)

        Args:
           resource_type (str): The resource type to format.
           lower (bool): Return type in all lower case

        Returns:
            (str): The formatted resource type.
        """
    if resource_type is not None:
        resource_type = resource_type.replace(' ', '_')
        if lower:
            resource_type = resource_type.lower()
    return resource_type
