code: function ensureBufferSize(buffer, minimumSize, contentSize) {
          if (buffer.length >= minimumSize) {
              return buffer;
          }
          var newBuffer = new Buffer(minimumSize);
          if (contentSize) {
              buffer.copy(newBuffer, 0, 0, contentSize);
          } else {
              buffer.copy(newBuffer);
          }
          return newBuffer;
      }
docs: Helper Functions ----------------