def depends(target, *user_deps)
      target = expand_varref(target.to_s)
      user_deps = user_deps.map {|ud| expand_varref(ud)}
      @user_deps[target] ||= []
      @user_deps[target] = (@user_deps[target] + user_deps).uniq
      build_after(target, user_deps)
    end
def depends(target, *user_deps)
      target = expand_varref(target.to_s)
      user_deps = user_deps.map {|ud| expand_varref(ud)}
      @user_deps[target] ||= []
      @user_deps[target] = (@user_deps[target] + user_deps).uniq
      build_after(target, user_deps)
    end
Manually record a given target as depending on the specified files.

 @param target [String,BuildTarget] Target file.
 @param user_deps [Array<String>] Dependency files.

 @return [void]