Function parse_unique_id_element 

pub fn parse_unique_id_element(
    element: &XmlElement,
    unique_id_elements: Option<&str>,
) -> String

Get a unique ID for an element, using configured fields or a hash of the outer element when no configured field exists in the subtree.

Hashing must be performed on the outer element (not on whatever inner child the search happened to visit first) so siblings whose first nested child shares a value - e.g. a list of <actionOverrides> that all start with <actionName>View</actionName> - still produce distinct filenames reflecting their distinct content.