def get_class_by_name( name )
      raise "get_class_by_name #{name}.#{name.class}" unless name.is_a?(Symbol)
      c = classes[name]
      #puts "MISS, no class #{name} #{name.class}" unless c # " #{classes}"
      #puts "CLAZZ, #{name} #{c.get_type.get_length}" if c
      c
    end
def get_class_by_name( name )
      raise "get_class_by_name #{name}.#{name.class}" unless name.is_a?(Symbol)
      c = classes[name]
      #puts "MISS, no class #{name} #{name.class}" unless c # " #{classes}"
      #puts "CLAZZ, #{name} #{c.get_type.get_length}" if c
      c
    end
get a class by name (symbol)
 return nili if no such class. Use bang version if create should be implicit