Warning about unused type variables during precompilation

[3f6a]

The following warnings are generated during precompilation of this package:

WARNING: method definition for getlength at ~/.julia/packages/Phylo/jUyqV/src/Interface.jl:1038 declares type variable N but does not use it.
WARNING: method definition for getlength at ~/.julia/packages/Phylo/jUyqV/src/Interface.jl:1043 declares type variable N but does not use it.
WARNING: method definition for _addoutbound! at ~/.julia/packages/Phylo/jUyqV/src/Tree.jl:431 declares type variable N but does not use it.
WARNING: method definition for noderoute at ~/.julia/packages/Phylo/jUyqV/src/routes.jl:162 declares type variable RT but does not use it.
WARNING: method definition for _handlez at ~/.julia/packages/Phylo/jUyqV/src/plot.jl:155 declares type variable T but does not use it.