def provides?(*names)
      names.flatten.any? do |name|
        if name.respond_to?(:to_sym)
          has_field?(name) || has_field?(aliases[name.to_sym])
        else
          false
        end
      end
    end
def provides?(*names)
      names.flatten.any? do |name|
        if name.respond_to?(:to_sym)
          has_field?(name) || has_field?(aliases[name.to_sym])
        else
          false
        end
      end
    end
Returns true if the Entry has a field (or alias) for any of the passed-in names.