statsmodels/statsmodels — pull request #1772 by josef-pkt (2014-06-18 21:29:48+00:00)
Title: REF: cov_params allow case of only cov_params_default is defined 

see #1730

this is an extension for new models that might not define normalized_cov_params.

(no specific unit tests, since we don't have a model yet that doesn't define normalized_cov_params, I think)