nl_tokens: Merge a branch / commit into a branch and update that branch s tree .
pl_tokens: function merge ( repoState , driver , from , into , options = { } ) { <mask> = Object . assign ( { fetch : true } , options ) ; let updatedInto ; // closure return driver . merge ( from , into , { message : options . message } ) // Can fail here with ERRORS.CONFLICT . then ( function updateInto ( mergeCommit ) { if ( ! mergeCommit ) { // Was a no op return repoState ; } else { updatedInto = into . merge ( { commit : mergeCommit } ) ; repoState = repoState . updateBranch ( into , updatedInto ) ; // invalidate working state return RepoUtils . updateWorkingState ( repoState , into , null ) ; } } ) . then ( function fetchTree ( repositoryState ) { if ( ! options . fetch ) { return repositoryState ; } else { return RepoUtils . fetchTree ( repositoryState , driver , updatedInto ) ; } } ) ; }