sbt - What does a bare line on its own do? -

in .sbt file, have copy-pasted lines readmes, of have no idea i'm doing. example is, after adding sbt-revolver plugins.sbt, writing line

revolver.settings 

my current understanding of magically adding re-start , re-stop commands sbt. have been led understand line in .sbt file not, in fact, perform magic, rather creates key , associates value it.

what keys such line set, , value? equivalent statement in .scala build definition?

*.sbt files can take bare dslentry include setting[t] , seq[setting[t]].

an expression somestring := "a" or someseq += "b" setting specific t type.

these settings values though, define transformation (change, add, append, etc) of different parts of build, folded build state , structure.

in example revolver.settings seq[setting[_]] defines default setup of using sbt-revolver.

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if setting in project/*.scala need assign root project, either:

• the sole project in build
• the project aggregates other (sub) projects.

therefore like:

import sbt._, keys._  object build extends build {   val bippy = project in file(".") settings revolver.settings }