bson/src/main/org/bson/io/Bits.java
public static long readLong(final InputStream inputStream, final byte[] buffer) throws IOException {
        readFully(inputStream, buffer, 8);
        return readLong(buffer);
    }
public static long readLong(final InputStream inputStream, final byte[] buffer) throws IOException {
        readFully(inputStream, buffer, 8);
        return readLong(buffer);
    }
Reads and returns a single long value from the input stream.

@param inputStream the input stream to read from
@param buffer the buffer to write the input stream bytes into
@return the long value
@throws IOException if there's an error reading from the {@code inputStream}