question: long readDWord ( ) throws IOException { int b0 = m_in . read ( ) ; int b1 = m_in . read ( ) ; int b2 = m_in . read ( ) ; int b3 = m_in . read ( ) ; long value = ( ( b3 << 24 ) & 0xff000000 ) | ( ( b2 << 16 ) & 0xff0000 ) | ( ( b1 << 8 ) & 0xff00 ) | ( b0 & 0xff ) ; return value ; }
target:  Extract the next 4 bytes, which form a 32b integer, from the stream