ProteinBuilderTool { public static IBioPolymer createProtein(String sequence) throws CDKException { return createProtein(sequence, DefaultChemObjectBuilder.getInstance()); }  static IBioPolymer addAminoAcidAtNTerminus(IBioPolymer protein, IAminoAcid aaToAdd, IStrand strand,
            IAminoAcid aaToAddTo); static IBioPolymer addAminoAcidAtCTerminus(IBioPolymer protein, IAminoAcid aaToAdd, IStrand strand,
            IAminoAcid aaToAddTo); static IBioPolymer createProtein(String sequence); static IBioPolymer createProtein(String sequence, IChemObjectBuilder builder);  }
@Test public void testCreateProtein() throws Exception { IBioPolymer protein = ProteinBuilderTool.createProtein("GAGA", SilentChemObjectBuilder.getInstance()); Assert.assertNotNull(protein); Assert.assertEquals(4, protein.getMonomerCount()); Assert.assertEquals(1, protein.getStrandCount()); Assert.assertEquals(18 + 1, protein.getAtomCount()); Assert.assertEquals(14 + 3 + 1, protein.getBondCount()); }