public void setFieldCompletenessImportance(float fieldCompletenessImportance) {
        ensureNotFrozen();
        this.fieldCompletenessImportance = fieldCompletenessImportance;
    }
Returns a number between 0 and 1 which determines the importancy of field completeness in relation to
query completeness in the <code>match</code> and <code>completeness</code> metrics. Default is 0.05
searchlib/src/main/java/com/yahoo/searchlib/ranking/features/fieldmatch/FieldMatchMetricsParameters.java