MAINT: Add sanity check to ensure usecols is correct.
MAINT: Add sanity check to ensure usecols is correct.

endolith/numpy,mattip/numpy,mhvk/numpy,rgommers/numpy,anntzer/numpy,jakirkham/numpy,charris/numpy,jakirkham/numpy,seberg/numpy,rgommers/numpy,seberg/numpy,seberg/numpy,mhvk/numpy,jakirkham/numpy,jakirkham/numpy,charris/numpy,numpy/numpy,pdebuyl/numpy,numpy/numpy,pdebuyl/numpy,anntzer/numpy,charris/numpy,numpy/numpy,endolith/numpy,anntzer/numpy,charris/numpy,mhvk/numpy,jakirkham/numpy,mhvk/numpy,mattip/numpy,pdebuyl/numpy,rgommers/numpy,numpy/numpy,mattip/numpy,mhvk/numpy,anntzer/numpy,endolith/numpy,pdebuyl/numpy,rgommers/numpy,seberg/numpy,endolith/numpy,mattip/numpy