def set( *severities )
      @severities = Yell::Severities.map { true }
      severity = severities.length > 1 ? severities : severities.first

      case severity
      when Array then at(*severity)
      when Range then gte(severity.first).lte(severity.last)
      when String then interpret(severity)
      when Integer, Symbol then gte(severity)
      when Yell::Level then @severities = severity.severities
      end
    end
def set( *severities )
      @severities = Yell::Severities.map { true }
      severity = severities.length > 1 ? severities : severities.first

      case severity
      when Array then at(*severity)
      when Range then gte(severity.first).lte(severity.last)
      when String then interpret(severity)
      when Integer, Symbol then gte(severity)
      when Yell::Level then @severities = severity.severities
      end
    end
Create a new level instance.

 @example Enable all severities
   Yell::Level.new

 @example Pass the minimum possible severity
   Yell::Level.new :warn

 @example Pass an array to exactly set the level at the given severities
   Yell::Level.new [:info, :error]

 @example Pass a range to set the level within the severities
   Yell::Level.new (:info..:error)

 @param [Integer,String,Symbol,Array,Range,nil] severity The severity for the level.
 Set the severity to the given format