   [0,red,edge label={node[midway,left] {A}}              [0,red,edge label={node[midway,right] {B}}]             [0,red,edge label={node[midway,right] {C}}]             ]    [0,red,edge label={node[midway,right] {B}}             [0,red,edge label={node[midway,right] {A}}]             [0,red,edge label={node[midway,right] {C}}]             ]         [0,red,edge label={node[midway,right] {C}}             [0,red,edge label={node[midway,right] {A}}]             [0,red,edge label={node[midway,right] {B}}]             ] 