pub fn require_header<Block: BlockT>(
	db: &KeyValueDB,
	col_index: Option<u32>,
	col: Option<u32>,
	id: BlockId<Block>,
) -> client::error::Result<Block::Header> {
	read_header(db, col_index, col, id)
		.and_then(|header| header.ok_or_else(|| client::error::ErrorKind::UnknownBlock(format!("{}", id)).into()))
}
/// Required header from the database.
Required header from the database.
Required header from the database .
pub fn require_header<Block: BlockT>(
	db: &KeyValueDB,
	col_index: Option<u32>,
	col: Option<u32>,
	id: BlockId<Block>,
) -> client::error::Result<Block::Header> {
	read_header(db, col_index, col, id)
		.and_then(|header| header.ok_or_else(|| client::error::ErrorKind::UnknownBlock(format!("{}", id)).into()))
}
pub fn require_header < Block : BlockT > ( db : & KeyValueDB , col_index : Option < u32 > , col : Option < u32 > , id : BlockId < Block > , ) -> client :: error :: Result < Block :: Header > { read_header ( db , col_index , col , id ) . and_then ( | header | header . ok_or_else ( | | client :: error :: ErrorKind :: UnknownBlock ( format ! ( " " id ) ) . into ( ) ) ) }
Required header from the database.
Required header from the database .
db
&KeyValueDB
col_index
Option<u32>
col
Option<u32>
id
BlockId<Block>
db
&KeyValueDB
col_index
Option<u32>
col
Option<u32>
id
BlockId<Block>