normal_block    ::=  ExampleGroup |  Describe |  Context |  Example |  Specify |  It
focused_block   ::= fExampleGroup | fDescribe | fContext | fExample | fSpecify | fIt
skipped_block   ::= xExampleGroup | xDescribe | xContext | xExample | xSpecify | xIt
end_block       ::=  End
normal_example  ::=  Example |  Specify |  It
focused_example ::= fExample | fSpecify | fIt
skipped_example ::= xExample | xSpecify | xIt
oneline_example ::=  Todo
begin_block     ::= $normal_block | $focused_block | $skipped_block
block_example   ::= $normal_example | $focused_example | $skipped_example
example         ::= $block_example | $oneline_example