self.new creates a BreadcrumbBlock. It does not take any block-specific arguments. A breadcrumb block has no block-specific content; its breadcrumb value is an empty object.

block = BreadcrumbBlock.new
block.block_json
# => {"type"=>"breadcrumb", "object"=>"block", "breadcrumb"=>{}}

A BreadcrumbBlock cannot have child blocks and has no block-specific mutable properties. General operations such as retrieval and deletion are inherited from Block.