| Proto and AutoValue builders provide a fluent interface for constructing |
| instances. Unlike argument lists, however, they do not prevent the user from |
| providing multiple values for the same field. |
| |
| Setting the same field multiple times in the same chained expression is |
| pointless (as the intermediate value will be overwritten), and can easily mask a |
| bug, especially if the setter is called with *different* arguments. |
| |
| ```java |
| return MyProto.newBuilder() |
| .setFoo(copy.getFoo()) |
| .setFoo(copy.getBar()) |
| .build(); |
| ``` |
