Generate sample for Monte Carlo integration in the multiple setting
get_sample_multiple_normal(Delta1, Delta2, in1, in2, rho)
a randomly generated data frame
assumed true treatment effect given as difference in means for endpoint 1
assumed true treatment effect given as difference in means for endpoint 2
amount of information for Delta1
in terms of sample size
amount of information for Delta2
in terms of sample size
correlation between the two endpoints