fails:Enumerator::Lazy#grep requires an argument
fails:Enumerator::Lazy#grep returns a new instance of Enumerator::Lazy
fails:Enumerator::Lazy#grep sets nil to size
fails:Enumerator::Lazy#grep calls the block with a gathered array when yield with multiple arguments
fails:Enumerator::Lazy#grep when the returned lazy enumerator is evaluated by Enumerable#first stops after specified times when not given a block
fails:Enumerator::Lazy#grep when the returned lazy enumerator is evaluated by Enumerable#first stops after specified times when given a block
fails:Enumerator::Lazy#grep on a nested Lazy sets nil to size
fails:Enumerator::Lazy#grep on a nested Lazy when the returned lazy enumerator is evaluated by Enumerable#first stops after specified times when not given a block
fails:Enumerator::Lazy#grep on a nested Lazy when the returned lazy enumerator is evaluated by Enumerable#first stops after specified times when given a block
