Arguments to IMPORT must either end with ".*" or else specify a fully qualified class name

Error: File: dens_times_SpeedOfSound_critical.m Line: 2 Column: 8

Arguments to IMPORT must either end with ".*" or else specify a fully qualified class name: "py.CoolProp.CoolProp.PropsSI" fails this test.

Why do I get the above error when I run the below script? (matlab2017b)

import py.CoolProp.CoolProp.PropsSI; 
P0 = 10:10:300;
T0 = 110:10:400;
c1 = [];
dens1 = [];
gamma = 1.304; 
T1 = 2*T0/(gamma+1);
P1 = P0/((gamma+1)/2)^(gamma/(gamma-1));
for i = 1:1:length(P1)
    for j = 1:1:length(T1)
        c1 = [c1,PropsSI('A','T',T1(j),'P',P1(i)*100000,'methane')];
        dens1 = [dens1,PropsSI('D','T',T1(j),'P',P1(i)*100000,'methane')];
    end
end
c1 = reshape(c1, [30,30]);
c1 = c1';
dens1 = reshape(dens1, [30,30]);
dens1 = dens1';
R1 = c1.*dens1;
[C,h] = contour(T0,P0,R1, [10000:10000:700000]);
clabel(C,h)commen
xlabel('T stagnation @ injector / k')
ylabel('P stagnation @ injector / bar')
title('Evolution of c1*dens1 as a function of T and P stagnation [kg/m2/s]')
mass_flow = (103.2/2000)/0.03;
Area1 = mass_flow./R1; %m2
diameter1 = 1000*sqrt(Area1.*4/pi()); %mm
figure
[D,t] = contour(T0,P0,diameter1, [0.5:0.5:15]);
clabel(D,t)
title('Injector diameter as a function of T and P stagnation [mm]')
xlabel('T stagnation @ injector / k')
ylabel('P stagnation @ injector / bar')