Bug when copying Date object from one table to another

To reproduce

Run the following code to copy a complex datatype (e.g., Date) from one table to another:

import JSDB from '@small-tech/jsdb'

const db = JSDB.open('test')

db.a = {
  x: new Date()
}

db.b = []

const x = db.a.x
db.b.push (x)

What should happen

It should work.

What actually happens

Error:

file:///home/aral/sandbox/jsdb-test/node_modules/@small-tech/jsdb/lib/JSDF.js:81
        serialisedValue = `new Date('${value.toJSON()}')`
                                             ^

TypeError: this is not a Date object.
    at Proxy.valueOf (<anonymous>)
    at Proxy.[Symbol.toPrimitive] (<anonymous>)
    at Proxy.toJSON (<anonymous>)
    at Function.serialise (file:///home/aral/sandbox/jsdb-test/node_modules/@small-tech/jsdb/lib/JSDF.js:81:46)
    at Function.serialise (file:///home/aral/sandbox/jsdb-test/node_modules/@small-tech/jsdb/lib/JSDF.js:63:30)
    at DataProxy.setHandler (file:///home/aral/sandbox/jsdb-test/node_modules/@small-tech/jsdb/lib/DataProxy.js:117:25)
    at Proxy.push (<anonymous>)
    at file:///home/aral/sandbox/jsdb-test/index.js:6:6
    at ModuleJob.run (internal/modules/esm/module_job.js:170:25)
    at async Loader.import (internal/modules/esm/loader.js:178:24)