// Add simple text
ReferencePropertyDefinition textProperty = new ReferencePropertyDefinition();
textProperty.setName("person");
textProperty.setMandatory(true);
textProperty.setType("cm:person");
group.addFormProperty(textProperty);
definition.addStep(humanStep);
WorkflowDefinitionConversion conversion = conversionFactory.createWorkflowDefinitionConversion(definition);
conversion.convert();