Issue with gpp reading in readFluxdata function

[vflo]

In line 220 of the function readFluxdata, the conditional might be incorrect.

    else if (is.null(fluxnet_data$GPP)) {
      gpp <- xts(fluxnet_data$GPP_st_ANN * t_conv_f *1e-06, ind)
    }

Shouldn't this be:
!is.null(fluxnet_data$GPP_st_ANN)