public void setRelatednessImportance(float relatednessImportance) {
        ensureNotFrozen();
        this.relatednessImportance = relatednessImportance;
    }
Returns the normalized importance of relatedness used in the <code>match</code> metric. Default: 0.9
searchlib/src/main/java/com/yahoo/searchlib/ranking/features/fieldmatch/FieldMatchMetricsParameters.java