code: protected void runScript(String mapperScript, Slurper slurper, Builder builder)
              throws ActivityException, TransformerException {
  
          CompilerConfiguration compilerConfig = new CompilerConfiguration();
          compilerConfig.setScriptBaseClass(CrossmapScript.class.getName());
  
          Binding binding = new Binding();
          binding.setVariable("runtimeContext", getRuntimeContext());
          binding.setVariable(slurper.getName(), slurper.getInput());
          binding.setVariable(builder.getName(), builder);
          GroovyShell shell = new GroovyShell(getPackage().getCloudClassLoader(), binding, compilerConfig);
          Script gScript = shell.parse(mapperScript);
          gScript.run();
      }
docs: Invokes the builder object for creating new output variable value.