code: static public byte[] expandByteArray(byte[] src, byte b) {
  
          int srcLength = (null != src) ? src.length : 0;
          int totalLen = srcLength + 1;
          byte[] rc = new byte[totalLen];
          try {
              if (null != src) {
                  System.arraycopy(src, 0, rc, 0, srcLength);
              }
              rc[srcLength] = b;
          } catch (Exception e) {
              // no FFDC required
              // any error from arraycopy, we'll just return null
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "Exception " + e + " while copying.");
              }
              rc = null;
          }
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc,
                       "expandByteArray returning: [" + getEnglishString(rc) + "]");
          }
          return rc;
      }
docs: Helper method to append a byte to a byte array.
  
  @param src byte array
  @param b byte to be appended to the src byte array
  @return target byte array