Function add_feature_comparison_element 

pub fn add_feature_comparison_element(
    config_json: &str,
    params: AddFeatureComparisonParams<'_>,
) -> Result<String>

Add a feature comparison element (same as add_feature_comparison, for compatibility)

Arguments

• config_json - JSON configuration string
• params - Feature comparison parameters (ftype_id, felem_id required; others optional)

Returns

Modified configuration JSON string