can
Returns whether the font weight of the given block can be toggled between bold and normal.
Parameters
the text block block whose font weight should be toggled.
the start index of the range whose whose font weight should be toggled. If the value is negative and the block is currently being edited, this will fall back to the start of the current cursor index / selected range. If the value is negative and the block is not being edited, this will fall back to the start of the entire text range.
the index after the last character whose whose font weight should be toggled. If the value is negative and the block is currently being edited, this will fall back to the end of the current cursor index / selected range. If the value is negative and the block is not being edited, this will fall back to the end of the entire text range.