I need to read test data field information with a groovy.

I'm developping a groovy to read information from test cases and copy this in labels.

I can read the field preconditions because because is a custom field,

def cField = customFieldManager.getCustomFieldObject("customfield_14150");

but I don't know hwo to access to Test Details information like Test Data. I'm sure it must a way to read this fields. 

Please, can you help me?