code: func NewFilteringTokenFilter(spi FilteringTokenFilterSPI,
  	version util.Version, in TokenStream) *FilteringTokenFilter {
  	ans := &FilteringTokenFilter{
  		spi:         spi,
  		input:       in,
  		TokenFilter: NewTokenFilter(in),
  		version:     version,
  		first:       true,
  	}
  	ans.posIncrAtt = ans.Attributes().Add("PositionIncrementAttribute").(PositionIncrementAttribute)
  	ans.enablePositionIncrements = true
  	return ans
  }
docs: /* Creates a new FilteringTokenFilter. */