public Builder clear() {
        super.clear();
        if (verticesBuilder_ == null) {
          vertices_ = java.util.Collections.emptyList();
          bitField0_ = (bitField0_ & ~0x00000001);
        } else {
          verticesBuilder_.clear();
        }
        area_ = 0D;
        bitField0_ = (bitField0_ & ~0x00000002);
        perimeter_ = 0D;
        bitField0_ = (bitField0_ & ~0x00000004);
        if (centerBuilder_ == null) {
          center_ = org.bwapi.proxy.messages.BasicTypes.Position.getDefaultInstance();
        } else {
          centerBuilder_.clear();
        }
        bitField0_ = (bitField0_ & ~0x00000008);
        if (holesBuilder_ == null) {
          holes_ = java.util.Collections.emptyList();
          bitField0_ = (bitField0_ & ~0x00000010);
        } else {
          holesBuilder_.clear();
        }
        return this;
      }