class Asciidoctor::Extensions::Registry

def find_block_extension name

corresponding BlockProcessor or nil if a match is not found.
Returns the [Extension] object stored in the registry that proxies the

name - the String or Symbol (coersed to a Symbol) macro name

to handle block content with the name.
Public: Retrieves the {Extension} proxy object for the BlockProcessor registered 
def find_block_extension name
  @block_extensions[name.to_sym]
end