How to use family Filter response ()

[thefirecode]

I cannot understand how to use them with FIR filters and get the frequency and phase response. My code example is below. How do I cast the variable "h" into type filter::FilterCoefficients{:z} that is what I am confused about what types are these can you give me an example?

#=
using DSP,ReadWriteDlm2

N=remezord(0.25,0.355, db2amp(0.1)-1, db2amp(0.25)-1)

h=remez(N,[(0.0, 0.25)=>1,(0.355,0.5)=>0])

H, w = freqresp(FIRFilter(h))
=#

[wheeheee]

Duplicate of #511 and #185. This is a known issue, with this workaround:

H, w = freqresp(PolynomialRatio(h, 1))