| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/prometheus/common/model | Package model contains common data structures that are shared across Prometheus components and libraries. |
| math | Package math provides basic constants and mathematical functions. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| time | Package time provides functionality for measuring and displaying time. |