change return types and document some methods in AtlasDriver
change return types and document some methods in AtlasDriver

openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro,openhumanoids/oh-distro