Class: Direction LR
`direction LR` lays the classes out left to right, as mermaid.js does (#2116): each level is a column and the markers face the new axis.
class-direction-lr.mmd
classDiagram
direction LR
class Animal {
+String name
+eat() void
}
Animal <|-- Dog
Animal <|-- Cat
Animal "1" --> "*" Toy : owns