code: func MatchCallByType(n ast.Node, ctx *Context, requiredType string, calls ...string) (*ast.CallExpr, bool) {
  	if callExpr, ok := n.(*ast.CallExpr); ok {
  		typeName, callName, err := GetCallInfo(callExpr, ctx)
  		if err != nil {
  			return nil, false
  		}
  		if typeName == requiredType {
  			for _, call := range calls {
  				if call == callName {
  					return callExpr, true
  				}
  			}
  		}
  	}
  	return nil, false
  }
docs: // MatchCallByType ensures that the node is a call expression to a
  // specific object type.
  //
  // Usage:
  // 	node, matched := MatchCallByType(n, ctx, "bytes.Buffer", "WriteTo", "Write")
  //