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Description
Currently, some Mbed devices support any I2C frequency, while other ones only support a limited subset. Furthermore, some of the HAL implementations (nRF52) round the frequency that you pass in if it's not supported, while others (STM32) generate an assertion failure. This behavior is very obtuse to a user and needs to be standardized. In a perfect world, all HALs should support arbitrary I2C frequencies. If that's not feasible, we should have some way for code to check what frequency actually ended up getting set (and update docs accordingly).