GlyphSubstitutionTable gsub = tf.getGSUB();
assertTrue ( gsub != null );
GlyphSubstitutionSubtable[] sta = findGSUBSubtables ( gsub, script, language, feature, lid );
assertTrue ( sta != null );
assertTrue ( sta.length > 0 );
ScriptContextTester sct = findScriptContextTester ( script, language, feature );
String[][][] tia = (String[][][]) td[5]; // test instance array
for ( String[][] ti : tia ) { // test instance
if ( ti != null ) {
if ( ti.length > 1 ) { // must have at least input and output glyph id arrays
String[] igia = ti[0]; // input glyph id array