I'm attempting to use the net.liftweb.mocks.MockHttpServletRequest for some testing and I've run into a problem. Currently, there are some fields like "contentType" which are set as null and do not have an explicit type. This causes problems when I try to redefine the var's to a new value.

Here's an example of the failure:

scala> new net.liftweb.mocks.MockHttpServletRequest
res0: net.liftweb.mocks.MockHttpServletRequest = net.liftweb.mocks.MockHttpServletRequest@56426132

scala> res0.contentType = "application/x-www-form-urlencoded"
<console>:5: error: type mismatch;
found   : java.lang.String("application/x-www-form-urlencoded")
required: Null
      res0.contentType = "application/x-www-form-urlencoded"
                         ^

Could we change the definition of those vars to include the String type?