Rails ERD Customization

Question

Can you help me use the Customization Options of Rails ERD to generate a diagram that displays the primary keys and timestamps attributes.

How do I write this into irb terminal? This is what I tried:

$ rake erd primary_keys, timestamps

GitHub lists the Customization Options, but I'm not understanding how to write the attributes.

attributes             <type,...> | false

  Specifies which attributes to include in the diagram output. This can be any   
  combination of the following attribute types:

  foreign_keys  any foreign key column in use for associations
  primary_keys  the primary key column (typically id)
  timestamps    any of the 'magic' timestamp columns (created_at/on,updated_at/on)
  inheritance   the single table inheritance column (typically type)
  *content       all other columns
  *To hide attributes altogether, set this option to false. Default value: content

Thanks.

Answer 1

I think it would be rake erd attributes=primary_keys,timestamps.