code: func (obj *Global) GetBNF(ctx context.Context, bnfType string) ([]*BNFDef, error) {
  	result := &struct {
  		BnfDefs []*BNFDef	`json:"qBnfDefs"`
  	} {}
  	err := obj.rpc(ctx, "GetBNF", result, bnfType)
  	return result.BnfDefs, err 
  }
docs: // Gets the current Backus-Naur Form (BNF) grammar of the Qlik engine scripting language. The BNF rules define the syntax for the script statements and the script or chart functions.
  // In the Qlik engine BNF grammar, a token is a string of one or more characters that is significant as a group. For example, a token could be a function name, a number, a letter, a parenthesis, and so on.
  //
  // Parameters:
  //
  // ◾ bnfType   -   Returns a set of rules defining the syntax for:
  // 
  // • The script statements and the script functions if qBnfType is set to S.
  // 
  // • The chart functions if qBnfType is set to E.
  // 
  // One of:
  // 
  // • S or SCRIPT_TEXT_SCRIPT
  // 
  // • E or SCRIPT_TEXT_EXPRESSION
  //