Protocol
We use the following protocol to work with the storage
{ query: {}, doc: {}, docs: [], limit: 10, fields: {}, sort: {}, skip: 0 }
query - object to form selection criteria
doc - object to update a document
docs - array of objects to create documents
limit - parameter setting a limit for chosen documents
fields - object describing what fields will be chosen in the document
sort - object describing rules of sorting
skip - parameter setting the margin for selection