def _pv_opts_lookup(opts, key)
        if opts.has_key?(key.to_s)
          opts[key.to_s]
        elsif opts.has_key?(key.to_sym)
          opts[key.to_sym]
        else
          nil
        end
      end
def _pv_opts_lookup(opts, key)
        if opts.has_key?(key.to_s)
          opts[key.to_s]
        elsif opts.has_key?(key.to_sym)
          opts[key.to_sym]
        else
          nil
        end
      end
Return the value of a parameter, or nil if it doesn't exist.