code: function( fromLBA, toLBA, buffer, callback ) {
  
      fromLBA = fromLBA || 0
      toLBA = toLBA || ( fromLBA + 1 )
  
      if( fromLBA > toLBA ) {
        var swap = fromLBA
        fromLBA = toLBA
        toLBA = swap
        swap = void 0
      }
  
      if( typeof buffer === 'function' ) {
        callback = buffer
        buffer = null
      }
  
      var self = this
      var from = this.blockSize * fromLBA
      var to = this.blockSize * toLBA
  
      debug( 'read_blocks', fromLBA, toLBA, buffer && buffer.length )
  
      this._read( from, to - from, buffer, callback )
  
      return this
  
    }
docs: Reads from one LBA to another
  @param  {Number} fromLBA
  @param  {Number} toLBA
  @param  {Buffer} buffer (optional)
  @param  {Function} callback( error, buffer, bytesRead )
  @return {BlockDevice}