| database/sql/driver | Package driver defines interfaces to be implemented by database drivers as used by package sql. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| gopkg.in/go-playground/validator.v8 | Package validator implements value validations for structs and individual fields based on tags. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |