TypeCalculator.generalize() produces bad types for Struct

The TypeCalculator.generalize strips all information about type and represented value (or values) when applied to a String. This behavior becomes problematic when generalizing a Struct type since it means that all information about the keys in that struct is lost and a printout of a generalized Struct becomes nonsensical. The struct:

Struct[{name => String[1], version => String[1]}]

becomes:

Struct[{'' => String, '' => String}]