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