message: Add: `objectToErrorString` util method
  To help list object keys and values when throwing errors
diff: @@ -278,6 +278,23 @@ export const padLeft = ({
  character?: any,
  } = {}): string => `${String(character).repeat(length - value.length)}${value}`;
  +/**
  + * Convert an object to a key (value) concatenated string.
  + * This is usefull to list values inside of error messages, where you can only pass in a string and
  + * not the whole object.
  + *
  + * @method objectToErrorString
  + *
  + * @param {Object} object The object to convert
  + *
  + * @return {[type]} The string containing the object's key (value) pairs
  + */
  +export const objectToErrorString = (object: Object = {}): string =>
  + Object.keys(object).reduce(
  + (allArgs, key) => `${allArgs}${key} (${String(object[key])}), `,
  + '',
  + );
  +
  const utils: {
  warning: (...*) => void,
  getRandomValues: (...*) => Uint8Array,
  @@ -285,6 +302,7 @@ const utils: {
  assertTruth: (...*) => boolean,
  bigNumber: (...*) => BN,
  padLeft: (...*) => string,
  + objectToErrorString: (...*) => string,
  } = Object.assign(
  {},
  {
  @@ -293,6 +311,7 @@ const utils: {
  assertTruth,
  bigNumber,
  padLeft,
  + objectToErrorString,
  },
  /*
  * Only export the `verbose` method for testing purpouses
  