Make formatChevrotainError static.

Author: LesterLyu

grammar/hooks.js

@@ -335,7 +335,7 @@ class FormulaParser {
         }
         if (this.parser.errors.length > 0) {
             const error = this.parser.errors[0];
-            throw this.utils.formatChevrotainError(error, inputText);
+            throw Utils.formatChevrotainError(error, inputText);
         }
         return res;
     }
@@ -368,7 +368,7 @@ class FormulaParser {
         }
         if (this.parser.errors.length > 0) {
             const error = this.parser.errors[0];
-            throw this.utils.formatChevrotainError(error, inputText);
+            throw Utils.formatChevrotainError(error, inputText);
         }
         return res;
     }

grammar/utils.js

@@ -386,7 +386,7 @@ class Utils {
         return obj instanceof FormulaError;
     }
 
-    formatChevrotainError(error, inputText) {
+    static formatChevrotainError(error, inputText) {
         let line, column, msg = '';
         // e.g. SUM(1))
         if (error instanceof NotAllInputParsedException) {