# File lib/facet/hash/keys_to_s.rb, line 32 def keys_to_s!( from_class=nil ) raise ArgumentError, "Parameter must be a class" unless from_class.kind_of?(Class) if from_class if from_class self.each_key{ |k| self[k.to_s]=self.delete(k) if k.respond_to?(:to_s) and k.class == from_class } else self.each_key{ |k| self[k.to_s]=self.delete(k) if k.respond_to?(:to_s) } end self end