New returns a new Pool struct.

ErrConflict is returned when the transaction being added is incompatible with the contents of the memory pool (Sender doesn't have enough GAS to pay for all transactions in the pool).

ErrConflictsAttribute is returned when the transaction conflicts with other transactions due to its (or theirs) Conflicts attributes.

ErrDup is returned when the transaction being added is already present in the memory pool.

ErrInsufficientFunds is returned when the Sender is not able to pay for the transaction being added irrespective of the other contents of the pool.

ErrOOM is returned when the transaction just doesn't fit in the memory pool because of its capacity constraints.

ErrOracleResponse is returned when the mempool already contains a transaction with the same oracle response ID and higher network fee.

Pool stores the unconfirmed transactions.

Feer is an interface that abstracts the implementation of the fee calculation.