function DxfReader (options) {
    const reader = this
    reader.options = options || {}

    reader.trackPosition = (reader.options.track !== false)
    if (reader.trackPosition) {
      reader.line = reader.column = reader.c = 0
    }
  }
Class DxfReader
A class to hold state while reading DXF formatted data.
@param {Object} [options] - options for parsing
@param {Boolean} [options.track=true] - track position for error reporting
@param {Boolean} [options.strict=false] - obey strict DXF specifications
@constructor

@example
const dxfPath = path.resolve(__dirname, 'circle10.dxf')
let src = fs.readFileSync(dxfPath, 'UTF8')
let reader = dxf.reader({track: true})
// setup state handling
reader.on('error',handleError)
reader.on('start',handleStart)
reader.on('end'  ,handleEnd)
// setup handling for groups of interest, skip the rest
reader.absorb(0,handleEntity)
// start the reader
reader.write(src).close()