Parsed documentation:
View on GitHub
Merges two attribute hashes.
This is the same as `to.merge!(from)`,
except that it merges id, class, and data attributes.

ids are concatenated with `"_"`,
and classes are concatenated with `" "`.
data hashes are simply merged.

Destructively modifies `to`.

@param to [{String => String,Hash}] The attribute hash to merge into
@param from [{String => Object}] The attribute hash to merge from
@return [{String => String,Hash}] `to`, after being merged
Please help! Open an issue on GitHub if this assessment is incorrect.