ph-schematron/src/main/java/com/helger/schematron/pure/preprocess/PSPreprocessor.java
@Nullable
  public PSSchema getForcedPreprocessedSchema (@Nonnull final PSSchema aSchema) throws SchematronPreprocessException
  {
    ValueEnforcer.notNull (aSchema, "Schema");

    final PreprocessorLookup aLookup = new PreprocessorLookup (aSchema);
    final PreprocessorIDPool aIDPool = new PreprocessorIDPool ();

    final PSSchema ret = new PSSchema (aSchema.getResource ());
    ret.setID (aIDPool.getUniqueID (aSchema.getID ()));
    ret.setRich (aSchema.getRichClone ());
    ret.setSchemaVersion (aSchema.getSchemaVersion ());
    ret.setDefaultPhase (aSchema.getDefaultPhase ());
    ret.setQueryBinding (aSchema.getQueryBinding ());
    if (m_bKeepTitles && aSchema.hasTitle ())
      ret.setTitle (aSchema.getTitle ().getClone ());
    if (aSchema.hasAnyInclude ())
      throw new SchematronPreprocessException ("Cannot preprocess <schema> with an <include>");
    for (final PSNS aNS : aSchema.getAllNSs ())
      ret.addNS (aNS.getClone ());
    // start ps are skipped
    for (final PSLet aLet : aSchema.getAllLets ())
      ret.addLet (aLet.getClone ());
    for (final PSPhase aPhase : aSchema.getAllPhases ())
      ret.addPhase (_getPreprocessedPhase (aPhase, aIDPool));
    for (final PSPattern aPattern : aSchema.getAllPatterns ())
    {
      final PSPattern aMinifiedPattern = _getPreprocessedPattern (aPattern, aLookup, aIDPool);
      if (aMinifiedPattern != null)
      {
        // Pattern without rules?
        if (aMinifiedPattern.getRuleCount () > 0 || m_bKeepEmptyPatterns)
          ret.addPattern (aMinifiedPattern);
      }
    }

    // Schema without patterns?
    if (aSchema.getPatternCount () == 0 && !m_bKeepEmptySchema)
      return null;

    // end ps are skipped
    if (m_bKeepDiagnostics && aSchema.hasDiagnostics ())
      ret.setDiagnostics (_getPreprocessedDiagnostics (aSchema.getDiagnostics ()));
    ret.addForeignElements (aSchema.getAllForeignElements ());
    ret.addForeignAttributes (aSchema.getAllForeignAttributes ());
    return ret;
  }
@Nullable
  public PSSchema getForcedPreprocessedSchema (@Nonnull final PSSchema aSchema) throws SchematronPreprocessException
  {
    ValueEnforcer.notNull (aSchema, "Schema");

    final PreprocessorLookup aLookup = new PreprocessorLookup (aSchema);
    final PreprocessorIDPool aIDPool = new PreprocessorIDPool ();

    final PSSchema ret = new PSSchema (aSchema.getResource ());
    ret.setID (aIDPool.getUniqueID (aSchema.getID ()));
    ret.setRich (aSchema.getRichClone ());
    ret.setSchemaVersion (aSchema.getSchemaVersion ());
    ret.setDefaultPhase (aSchema.getDefaultPhase ());
    ret.setQueryBinding (aSchema.getQueryBinding ());
    if (m_bKeepTitles && aSchema.hasTitle ())
      ret.setTitle (aSchema.getTitle ().getClone ());
    if (aSchema.hasAnyInclude ())
      throw new SchematronPreprocessException ("Cannot preprocess <schema> with an <include>");
    for (final PSNS aNS : aSchema.getAllNSs ())
      ret.addNS (aNS.getClone ());
    // start ps are skipped
    for (final PSLet aLet : aSchema.getAllLets ())
      ret.addLet (aLet.getClone ());
    for (final PSPhase aPhase : aSchema.getAllPhases ())
      ret.addPhase (_getPreprocessedPhase (aPhase, aIDPool));
    for (final PSPattern aPattern : aSchema.getAllPatterns ())
    {
      final PSPattern aMinifiedPattern = _getPreprocessedPattern (aPattern, aLookup, aIDPool);
      if (aMinifiedPattern != null)
      {
        // Pattern without rules?
        if (aMinifiedPattern.getRuleCount () > 0 || m_bKeepEmptyPatterns)
          ret.addPattern (aMinifiedPattern);
      }
    }

    // Schema without patterns?
    if (aSchema.getPatternCount () == 0 && !m_bKeepEmptySchema)
      return null;

    // end ps are skipped
    if (m_bKeepDiagnostics && aSchema.hasDiagnostics ())
      ret.setDiagnostics (_getPreprocessedDiagnostics (aSchema.getDiagnostics ()));
    ret.addForeignElements (aSchema.getAllForeignElements ());
    ret.addForeignAttributes (aSchema.getAllForeignAttributes ());
    return ret;
  }
Convert the passed schema to a pre-processed schema independent if it is
already minimal or not.

@param aSchema
The schema to be made minimal. May not be <code>null</code>
@return A minimal copy of the schema. May be <code>null</code> if the
original schema is not yet minimal and {@link #isKeepEmptySchema()}
is set to <code>false</code>.
@throws SchematronPreprocessException
In case a preprocessing error occurs