public ModifiableHyperBoundingBox computeMBR() {
    E firstEntry = getEntry(0);
    if(firstEntry == null) {
      return null;
    }
    // Note: we deliberately get a cloned copy here, since we will modify it.
    ModifiableHyperBoundingBox mbr = new ModifiableHyperBoundingBox(firstEntry);
    for(int i = 1; i < numEntries; i++) {
      mbr.extend(getEntry(i));
    }
    return mbr;
  }
public ModifiableHyperBoundingBox computeMBR ( ) { E firstEntry = getEntry ( 0 ) ; if ( firstEntry == null ) { return null ; } ModifiableHyperBoundingBox mbr = new ModifiableHyperBoundingBox ( firstEntry ) ; for ( int i = 1 ; i < numEntries ; i ++ ) { mbr . extend ( getEntry ( i ) ) ; } return mbr ; }
Recomputing the MBR is rather expensive.

@return MBR