Remove unnecessary methods

lib/utils/common.js

@@ -5,46 +5,6 @@ const jsesc = require('jsesc')
 const utils = require('../utils')
 
 class common extends utils {
-  /**
-   * Return stringified object
-   * @param obj
-   * @returns {string}
-   */
-  static objToString (obj) {
-    try {
-      return `${obj}`
-    } catch (e) {
-      return `[${e}]`
-    }
-  }
-
-  /**
-   * Return enumerable properties recursively
-   * @param obj
-   * @returns {Array}
-   */
-  static getAllProperties (obj) {
-    let list = []
-    while (obj) {
-      list = list.concat(Object.getOwnPropertyNames(obj))
-      obj = Object.getPrototypeOf(obj)
-    }
-    return list
-  }
-
-  /**
-   * Return all properties (non-recursive)
-   * @param obj
-   * @returns {Array}
-   */
-  static getKeysFromHash (obj) {
-    let list = []
-    for (let p in obj) {
-      list.push(p)
-    }
-    return list
-  }
-
   /**
    * Escape and quote a string
    * @param s - String to be quoted