I am facing problem in schemaTypes of Sanity io All the details are mentioned below Any problem regarding the question U can ask me

userSchema.js

    name:'abouts',
    title:'Abouts',
    type: 'document',
    fields:[
        {
            name:'title',
            title:'Title',
            type:'string'
        },
        {
            name:'description',
            title:'Description',
            type:'string'
        },
        {
            name:'imgUrl',
            title:'ImgUrl',
            type: 'image',
            options: {
              hotspot: true,
            },
        },

    ]
} 

schema.js

import createSchema from 'part:@sanity/base/schema-creator'
import schemaTypes from 'all:part:@sanity/base/schema-type'
import { userSchema } from './userSchema'

export default createSchema({
  
  name: 'default',
  types: schemaTypes.concat([userSchema]),
}) 

Now, schemaTypes is an OBJECT as we can check from "typeof" operator, I dont understand how can we use .concat() with an Object, like .concat() is an array function which can be applied with Array, So how schemaTypes.concat([userSchema]) is working correctly??

Please help me regarding this. Thanks