hpack/src/main/java/com/twitter/hpack/Decoder.java
public void setMaxHeaderTableSize(int maxHeaderTableSize) {
    maxDynamicTableSize = maxHeaderTableSize;
    if (maxDynamicTableSize < encoderMaxDynamicTableSize) {
      // decoder requires less space than encoder
      // encoder MUST signal this change
      maxDynamicTableSizeChangeRequired = true;
      dynamicTable.setCapacity(maxDynamicTableSize);
    }
  }
public void setMaxHeaderTableSize(int maxHeaderTableSize) {
    maxDynamicTableSize = maxHeaderTableSize;
    if (maxDynamicTableSize < encoderMaxDynamicTableSize) {
      // decoder requires less space than encoder
      // encoder MUST signal this change
      maxDynamicTableSizeChangeRequired = true;
      dynamicTable.setCapacity(maxDynamicTableSize);
    }
  }
Set the maximum table size.
If this is below the maximum size of the dynamic table used by the encoder,
the beginning of the next header block MUST signal this change.