message: Added jsdoc to validate methods, fixed string concat
  Ticket:
diff: @@ -243,6 +243,9 @@ export class TransactionBuilder extends BaseTransactionBuilder {
  }
  }
  + /**
  + * Check wallet owner addresses for wallet initialization transactions are valid or throw.
  + */
  private validateWalletInitializationFields(): void {
  if (this._walletOwnerAddresses === undefined) {
  throw new BuildTransactionError('Invalid transaction: missing wallet owners');
  @@ -250,17 +253,23 @@ export class TransactionBuilder extends BaseTransactionBuilder {
  if (this._walletOwnerAddresses.length !== 3) {
  throw new BuildTransactionError(
  - `Invalid transaction: wrong number of owners -- required: 3, ` + `found: ${this._walletOwnerAddresses.length}`,
  + `Invalid transaction: wrong number of owners -- required: 3, found: ${this._walletOwnerAddresses.length}`,
  );
  }
  }
  + /**
  + * Check if a contract address for the wallet was defined or throw.
  + */
  private validateContractAddress(): void {
  if (this._contractAddress === undefined) {
  throw new BuildTransactionError('Invalid transaction: missing contract address');
  }
  }
  + /**
  + * Check if the contract nonce or countar was defined or throw.
  + */
  private validateContractCounter(): void {
  if (this._contractCounter === undefined) {
  throw new BuildTransactionError('Invalid transaction: missing contract counter');
  