Support using a function to define a frame spine
Support using a function to define a frame spine

mhvk/astropy,astropy/astropy,mhvk/astropy,mhvk/astropy,astropy/astropy,mhvk/astropy,astropy/astropy,pllim/astropy,astropy/astropy,astropy/astropy,pllim/astropy,pllim/astropy,mhvk/astropy,pllim/astropy,pllim/astropy