I’d like to be able to modify the parameters in a `Distribution`

using a tuple. For example, something like this

```
using Distributions
x=Normal(1.0, 3.0)
# doesn't work
params(x) = (2.0, 4.0)
```

Is it possible to do something along these lines? I’d like to modify the parameters of a distribution in a more programmatic fashion, i.e. only having a tuples of parameter values to pass (where I know how many parameters are appropriate, as well as restrictions on negativity) to several different variables representing a `Distribution`

. My use case will look something like this

```
# vector of distributions
rvs=[Normal(), Gamma()]
# vector of tuple of params to pass to each random variable
parms=[(-1, 2), (3, 4)]
# update parameters of `rvs` with corresponding `tuple`
for i in 1:length(rvs)
params(rvs[i]) = parms[i] # change this how?
end
```