src/main/java/com/arpnetworking/steno/Logger.java
static @Nullable  String[] createKeysFromArray(
            @Nullable final String[] array, 
            @Nullable final String... keys) {
        if (isNullOrEmpty(keys)) {
            return array;
        }
        if (isNullOrEmpty(array)) {
            return keys;
        }
        final String[] combined = Arrays.copyOf(keys, array.length + keys.length);
        for (int i = 0; i < array.length; ++i) {
            combined[keys.length + i] = array[i];
        }

        return combined;
    }
static @Nullable  String[] createKeysFromArray(
            @Nullable final String[] array, 
            @Nullable final String... keys) {
        if (isNullOrEmpty(keys)) {
            return array;
        }
        if (isNullOrEmpty(array)) {
            return keys;
        }
        final String[] combined = Arrays.copyOf(keys, array.length + keys.length);
        for (int i = 0; i < array.length; ++i) {
            combined[keys.length + i] = array[i];
        }

        return combined;
    }
static @ Nullable String [ ] createKeysFromArray ( @ Nullable final String [ ] array , @ Nullable final String ... keys ) { if ( isNullOrEmpty ( keys ) ) { return array ; } if ( isNullOrEmpty ( array ) ) { return keys ; } final String [ ] combined = Arrays . copyOf ( keys , array . length + keys . length ) ; for ( int i = 0 ; i < array . length ; ++ i ) { combined [ keys . length + i ] = array [ i ] ; } return combined ; }
/* package private
/ * package private