anchor.diff:  
   ~~~
   
  -Here's an example of a custom container class like this:
  +The recommended way to create a custom container class is to sub-class the Array class, then add additional methods, like this:
   
   ~~~ruby
   # lib/memories.rb
   class MEMORIES_B294 < ::Array
  -
  -  def <<(sub_block)   # to meet sub_block_group requirement
  -    push (sub_block)
  -  end
  -
  -end
  -~~~
  -
  -Although nothing special is done in this example class, this `<<` method could be used here to do any special things as part of managing multiple sub_blocks
  -at the memory level.
  -
  -
  +  # Example of a custom method to print the names of all contained memories
  +  def print_ids
  +    # Since this class is based on Array, we can use all Array methods like 'each'
  +    # on the contained objects
  +    each { |mem| puts mem.id }
  +  end
  +end
  +
  +# All conventional Array methods are supported since we sub-classed Array
  +memories.size                   # => 3
  +memories.first                  # => <memory 0 instance>
  +memories.map { |mem| mem.id }   # => [:memory0, :memory1, :memory2]
  +
  +# Plus we have our custom method(s)
  +memories.print_ids
  +=>
  +memory0
  +memory1
  +memory2
  +~~~
  +
  +If you do not sub-class Array, then you will need to be sure to define a `<<` push type method:
  +
  +~~~ruby
  +# lib/memories.rb
  +class MEMORIES_B294
  +  def initialize
  +    @sub_blocks = {}
  +  end
  +  # Example of a custom << method to permit adding sub_blocks to container
  +  # Required for use with sub_block_group
  +  def <<(sub_block)
  +    @sub_blocks[sub_block.id] = sub_block
  +  end
  +  # Example of a custom method to print the names of all contained memories
  +  def print_ids
  +    each { |mem| puts mem.id }
  +  end
  +  # Example of custom 'each' method
  +  def each
  +    @sub_blocks.each_value do |sub_block|
  +      yield sub_block
  +    end
  +  end
  +end
  +
  +# Drawback is you only have methods defined in this class.
  +~~~
   
   #### Wash, Rinse, Repeat
   
  
positive.code: $dut.memory1.class               # MEMORY_64_B954
  $dut.memory2.class               # MEMORY_32_B954
  $dut.memories.class              # Array (Array of all 3 memory sub_blocks)
  ~~~
  
  In addition, a unique container class can also be used instead of an Array to contain the sub_block objects if desired.
  
  The only requirement is that the method `<<` exist for this container class.
  
  Example of using defining a sub_block_group with a custom container class:
  
  ~~~ruby
  # lib/soc/eagle_m352.rb
  
negative.code: 
  # lib/memories.rb
  class MEMORIES_B294 < ::Array
    def print_ids
      each { |mem| puts mem.id }
    end
  end
  
  # file: lib/nvm/control_d345.rb
  