code: @NonNull
      public EmailIntentBuilder bcc(@NonNull Collection<String> bcc) {
          checkNotNull(bcc);
          for (String email : bcc) {
              checkEmail(email);
          }
          this.bcc.addAll(bcc);
  
          return this;
      }
docs: Add an email address to be used in the "bcc" field.
  
  @param bcc
  the email addresses to add
  
  @return This {@code EmailIntentBuilder} for method chaining