Fix TestRouting.java
Fix TestRouting.java

- a lambda cannot specify its output type (contrary to C++)

or-tools/or-tools,google/or-tools,or-tools/or-tools,or-tools/or-tools,or-tools/or-tools,or-tools/or-tools,google/or-tools,google/or-tools,google/or-tools,google/or-tools,google/or-tools,or-tools/or-tools