xproc-engine-calabash/src/main/java/org/daisy/maven/xproc/calabash/Calabash.java
public void setConfiguration(File configFile) {
		if (configFile == null)
			nextConfig = null;
		else
			try {
				XProcConfiguration config = new XProcConfiguration("he", false);
				nextConfig = config.getProcessor().newDocumentBuilder()
					.build(new SAXSource(new InputSource(new FileReader(configFile)))); }
			catch (FileNotFoundException e) {
				throw new IllegalArgumentException("Config file does not exist", e); }
			catch (SaxonApiException e) {
					throw new RuntimeException(e); }
	}
public void setConfiguration(File configFile) {
		if (configFile == null)
			nextConfig = null;
		else
			try {
				XProcConfiguration config = new XProcConfiguration("he", false);
				nextConfig = config.getProcessor().newDocumentBuilder()
					.build(new SAXSource(new InputSource(new FileReader(configFile)))); }
			catch (FileNotFoundException e) {
				throw new IllegalArgumentException("Config file does not exist", e); }
			catch (SaxonApiException e) {
					throw new RuntimeException(e); }
	}
Settings from a custom calabash.xml