Function missing_field_rank 

pub fn missing_field_rank(
    missing: &Option<GrowerModelGenerationInvalidPartial>,
) -> i32

Return an integer rank for a missing partial step: 0 => partial is not missing anything (fully valid) 1 => MissingJustifiedGrowerTreeConfiguration 2 => MissingJustifiedStringSkeleton 3 => MissingStrippedStringSkeleton 4 => MissingCoreStringSkeleton 5 => MissingAnnotatedLeafHolderExpansions