code: public StrBuilder deleteFirst(final char ch) {
          for (int i = 0; i < size; i++) {
              if (buffer[i] == ch) {
                  deleteImpl(i, i + 1, 1);
                  break;
              }
          }
          return this;
      }
docs: Deletes the character wherever it occurs in the builder.
  
  @param ch  the character to delete
  @return this, to enable chaining