please have a look for actor with ====:
http://www.plantuml.com/plantuml/uml/JSqn3a8X48JXVayneVS29fftaDVCmdQo65WAOxoxOEMqyoN_CO8zPdq8SxIEnDDlQwTdEkOmQ087A99RVJOt3oJzHshR5UWB_5d5MpuYlDprkYyvpCjAV040
the same should be true for:
'agent', 'boundary', 'control', 'entity', 'interface', 'usecase'
==== should span the same way as in the example here:
http://www.plantuml.com/plantuml/uml/SoWkIImgAStDuKhEpot8pqlDAr58H68dSINgsYLPbQGMbyJasG91J1w8hP2N3wIu75BpKe1w0G00
(--------)