function prepareOnDown({
  interaction,
  pointer,
  event,
  eventTarget
}, scope) {
  if (interaction.interacting()) {
    return;
  }

  const actionInfo = getActionInfo(interaction, pointer, event, eventTarget, scope);
  prepare(interaction, actionInfo, scope);
}
Returns or sets the maximum number of concurrent interactions allowed.  By
default only 1 interaction is allowed at a time (for backwards
compatibility). To allow multiple interactions on the same Interactables and
elements, you need to enable it in the draggable, resizable and gesturable
`'max'` and `'maxPerElement'` options.

@alias module:interact.maxInteractions

@param {number} [newValue] Any number. newValue <= 0 means no interactions.